Leptin, a 16 kDa polypeptide hormone, implicated in various physiological processes, exerts its action through the leptin receptor, a member of the class I cytokine receptor family. Both leptin and leptin receptor have recently been implicated in processes leading to breast cancer initiation and progression in animal models and humans. An A to G transition mutation in codon 223 in exon 6 of the leptin receptor gene, resulting in glutamine to arginine substitution (Gln223Arg), lies within the first of two putative leptin-binding regions and may be associated with impaired signaling capacity of the leptin receptor. This study was designed to assess the role of this polymorphism in breast cancer susceptibility in Nigerian women.We utilized a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay to evaluate the association between the Gln223Arg polymorphism of the leptin receptor gene and breast risk in Nigeria in a case control study involving 209 women with breast cancer and 209 controls without the disease. Study participants were recruited from surgical outpatient clinics and surgical wards of four University Teaching Hospitals located in Midwestern and southeastern Nigeria between September 2002 and April 2004.LEPR 223Arg allele were at a modestly increased risk of breast cancer after adjusting for confounders . There was no association with postmenopausal breast cancer risk .Premenopausal women carrying at least one LEPR Gln223Arg polymorphism in the extracellular domain of the LEPR receptor gene is associated with a modestly increased risk of premenopausal breast cancer in Nigerian women.Our results suggest that the  LEPR), a member of the class I cytokine receptor family. The leptin receptor is a single transmembrane protein and has several alternatively spliced isoforms  that are distributed in many tissues [LEPRs have been detected in human breast epithelial cell lines, breast cancer-derived cell lines (T47-D and MCF-7) and in human breast cancer tissue specimens [Leptin, a 16 kDa polypeptide hormone produced predominantly by white adipose tissue ,3. In ad tissues ,8. LEPRspecimens -11. In apecimens -12.LEPR gene have been described. Chung et al. [LEPR Gln223Arg polymorphism is associated with variation in ligand binding; higher levels of ligand binding activity has been demonstrated in individuals homozygous for the G (LEPR Arg223Arg) allele than for carriers of the A (LEPR 223Gln) allele [Several single nucleotide polymorphisms (SNPs) in the g et al.  identifig et al. ,15, but ) allele .LEPR genes in breast cancer risk [LEPR Gln223Arg polymorphism and serum leptin levels, one study among college students in Greece [LEPR Gln223Arg) and homozygote (LEPR Arg223Arg) carriers of the G allele; the second study by Quinton et al. [LEPR genes in breast cancer susceptibility; one [LEPR gene, we have chosen in this exploratory study to evaluate the role of the LEPR Gln223Arg polymorphism in breast cancer susceptibility in Nigerian women since it is the most studied functional LEPR gene polymorphism in human subjects.Despite these premises, very few studies have considered the role of serum leptin levels and polymorphisms in leptin and cer risk -23. Fourcer risk -20 on plcer risk  and anotcer risk  reportedcer risk ,20 in thn Greece  reportedn et al.  among poThe recruitment of participants for this study from four University Teaching Hospitals located in southern Nigeria  has been described elsewhere ,25. BrieStudy participants signed informed consent after detailed explanation of the purpose, risks and benefits, confidentiality and rights of participants prior to recruitment. Data in respect of reproductive history, demographic characteristics, occupational exposure to pesticides and fertilizers and lifestyle choices including alcohol consumption and cigarette smoking were obtained using interviewer-administered questionnaires. Anthropometric measurements including height, weight, waist and hip circumferences were taken at the end of the interview.3-EDTA vacutainer tube from each of the study participants at the end of the interview. The buffy coat was prepared by centrifuging whole blood 2500 × g for 10 min at room temperature. All the samples were stored at -20°C in the Nigerian coordinating center at the University of Benin Teaching Hospital and later shipped to University of Pittsburgh in dry ice. Samples were stored at -80°C at the University of Pittsburgh until DNA extraction. DNA extraction from buffy coats (and clots for subjects with no buffy coats) was carried out using QIAamp DNA Mini Kits (for buffy coats) and QIAamp DNA Midi Kits (for blood clots) protocols . The extracted DNA was stored at 4°C until used for polymerase chain reaction (PCR) and restriction fragment length (RFLP) analysis.Ten milliliters (ml) blood sample was collected into one 10 ml KLEPR gene by a PCR-based restriction fragment length polymorphism (RFLP) assay. PCR amplification of an 80 bp fragment of the LEPR gene, including part of exon 6 that contains the polymorphism was carried out using forward primer: AAACTCAACGACACTCTCCTT and reverse primer: TGAACTGACATTAGAGGTGAC. A 50 μl PCR reaction mixture containing 2 μl of genomic DNA, 5 μl of deoxynucleotide triphosphates, 3 μl each of forward and reverse primers, 5 μl of 10× buffer, 1.5 μl of MgCl2 and 0.5 μl of Taq polymerase was placed in a thermocycler. After denaturing for 5 min at 95°C, the DNA was amplified for 35 cycles at 95°C for 30 sec, 59°C for 45 sec, and 72°C for 60 sec, followed by a 5 min extension at 72°C. A positive control containing genomic DNA and a negative control containing everything except DNA were included in the PCR experiment. Five μl of each PCR product, including the controls, were verified on a 3% agarose gel to ensure that the expected 80 bp product was generated.Genomic DNA from the cases and control subjects were analyzed for the presence of the A to G mutation at codon 223 of the LEPR codon 223) generated a unique 80 bp fragment, while the 80 bp fragment was divided into unique 58 bp and 22 bp fragments when position 668 contains a G. The gels were visualized by UV light and the RFLP gel electrophoresis products were read by two independent persons who were unaware of the identities of samples as either cases or controls. DNA extraction and RFLP assays employing Msp 1 restriction enzyme were successful in 209 cases and 209 control subjects; therefore the analysis is restricted to this sample of women.Restriction digest for the DNA fragment was carried out using Msp 1 restriction enzyme. Fifteen μl of the PCR product was digested for 16 h overnight at 37°C with 10 units of Msp 1 (New England Biolabs). The product of the restriction digest was mixed with 10 μl of loading dye and verified on a 3% agarose gel (with Ethidium bromide) electrophoresis in a 1× Tris-Borate-EDTA buffer at 200 V for 60 min. The presence of an A at position 668  software (Version 8.0). Although the original data was matched by age, the analysis of the genetic data was conducted on the unmatched sample, since DNA was not available on all the study participants. Therefore an unmatched analysis was conducted and an adjustment for age was performed. Unconditional logistic regression was used to assess the association between the A total of 418 female participants were recruited from the surgical outpatient clinics and surgical wards of the four University Teaching Hospitals in southern Nigeria. Two hundred and nine of them were being managed for various stages of breast cancer while the remaining 209 women, being treated for various non-malignant diseases in the same institutions served as control subjects. The ages of the cases and control subjects were similar with mean ages of 46.1 ± 12.63 years and 47.1 ± 13.50 years for cases and controls, respectively. Details on the associations between anthropometric, demographic and reproductive variables are reported elsewhere ,27.LEPR Gln223Arg variant is highly polymorphic in the Nigerian population. The distribution of the LEPR Gln223Arg alleles and genotypes are shown in Table LEPR 223Gln allele was similar in cases and controls with allele frequencies of 0.49 and 0.51, respectively while the frequency of the LEPR 223Arg allele was 0.51 and 0.49, respectively. The homozygous LEPR Gln223Gln genotype was slightly less common in the cases compared to the controls with genotype frequencies of 0.22 and 0.27, respectively while the heterozygous LEPR Gln223Arg genotype was equally distributed among cases and controls with frequency of 0.51 in both cases and control subjects. The homozygous Arg223Arg genotype was slightly more common in the cases compared to the controls with frequencies of 0.27 and 0.22, respectively. The distribution of the LEPR 223Gln and 223Arg alleles among the controls were in Hardy-Weinberg equilibrium overall and in both premenopausal and postmenopausal women.Our results indicate that the LEPR 223Gln allele was less frequent in premenopausal breast cancer cases compared to those without breast cancer with allele frequencies of 0.46 and 0.54, respectively. The wild-type LEPR Gln223Gln genotype was less frequent in the women with breast cancer compared to those without the disease, with genotype frequencies of 0.20 and 0.31, respectively.  and the homozygous mutant LEPR Arg223Arg genotype  had no significant increased risk of breast cancer.Compared to women with the LEPR 223Arg allele (LEPR Gln223Arg + LEPR Arg223Arg genotypes) was not associated a significant risk of breast cancer in these women . Adjusting for waist/hip ratio, a surrogate measure of obesity did not significantly alter the risk profile in these women as shown in Table The presence of at least one LEPR 223Arg allele (LEPR Gln223Arg + LEPR Arg223Arg): OR = 1.8, 95% CI 1.0–3.3, p = 0.05 . The homozygous LEPR Arg223Arg genotype was also associated with some modest increase in breast cancer risk . These risk profiles were unaltered when the analysis was adjusted for waist/hip ratio and age .Among premenopausal women, there was a marginally increased risk of breast cancer with the LEPR Gln223Arg polymorphism and breast cancer risk , Pima Indians (0.32), Arabs (0.34) but much lower than figures in Asian populations (0.85) [LEPR 223Arg allele frequency by racial groups, the study recruited only 26 blacks and racial admixture in the U.S. population may partly account for their finding. The International Hapmap Project reported LEPR 223Arg allele frequencies of 0.61 among Yorubas in Ibadan, Nigeria and 0.53 in African Americans. [The results of our study showed that the s (0.85) . Althougs (0.85)  reportedericans. LEPR Gln223Arg polymorphism and breast cancer risk showed that premenopausal women carrying at least one LEPR 223Arg allele were at a modestly increased risk of breast cancer ; the risk was unaltered after adjusting for waist/hip ratio and age . There was no association between the LEPR Gln223Arg polymorphism and breast cancer risk in postmenopausal women. Two studies [LEPR Gln223Arg polymorphism in relation to breast cancer risk; one [LEPR Gln223Arg and Arg223Arg genotypes, respectively). In addition, the authors noted that the presence of the LEPR 223Arg allele was associated with poorer overall survival. The second study by Woo et al. [LEPR 223Gln allele in the Korean population  and the small sample size of their study (45 breast cancer cases and 45 control subjects). Some investigators [LEPR Gln223Arg polymorphism and serum levels of leptin since there is some evidence associating serum leptin levels with breast cancer risk [LEPR Arg223Arg compared with those harboring at least one LEPR 223Gln allele. Another study of 220 postmenopausal women in the U.K. found significant association between serum leptin levels and the LEPR genotype [The evaluation of the relationship of the tigators ,18,21 hacer risk ,18. In agenotype .Although the actual mechanisms of leptin's role in breast cancer risk are not completely known, several lines of evidence provide support for leptin's broader physiological role, including the regulation of several neuroendocrine axes, some of which play a significant role in the pathogenesis of breast cancer. Leptin treatment corrects the hypogonadism of leptin-deficient ob/ob mice ,31 and sLEPR gene (LEPR Gln223Arg), a glutamine for an arginine with a change from neutral to positive, could affect the functionality of the receptor and alter its signaling capacity [LEPR Arg223Arg) and higher levels of leptin in the LEPR Arg223Arg homozygotes and our finding of increased premenopausal breast cancer risk in women carrying the LEPR 223Arg allele provides supportive evidence for this proposition. It is possible that the leptin polymorphism is in linkage disequilibrium with other genes that play a role in breast cancer risk.Tumor markers that are elevated in breast cancer can upregulate leptin production. These factors, including TNF-α, IL-1α, IL-1β, VEGF, and fibroblast growth factor 2 (FGF-2), raise leptin levels and promote tumor growth and differentiation ,41. In ecapacity ,42,43. TLEPR) gene in breast cancer susceptibility in most populations and its complete absence in sub-Saharan African populations. Much has been said about the mechanisms of leptin-induced carcinogenesis in animal models and correlation of serum leptin levels with breast cancer risk [LEPR Gln223Arg polymorphism on breast cancer may vary from one population to the other as a result of marked differences in the distribution of the alleles in different populations. The finding of interaction between LEPR Gln223Arg genotypes and menopausal status and obesity may also partly explain the differences in reports from various populations. In the developed countries with a much higher percentage of postmenopausal breast cancer and a higher proportion of obese women, LEPR Gln223Arg polymorphism may be expected to have more impact on risk of the disease compared to the Nigerian population with a lower prevalence of obesity. Some of the limitations of this study include use of both incident and prevalent cases of breast cancer. Given the report of poorer prognosis associated with the LEPR 223Arg allele in some studies, it is possible that some patients harboring this allele might have died earlier leaving us with more patients with the LEPR 223Gln allele. However, such a bias if prevent would result in underestimation of the risk associated with the putative high risk LEPR 223Arg allele. There is currently no breast cancer screening program in Nigeria; therefore patients with early pre-clinical disease may have been missed in our study. Use of hospital controls is necessitated by the limited research infrastructure such as poor communication facilities and lack of population-based cancer registries in developing countries such as Nigeria.An important observation is the paucity of epidemiological literature on the role of polymorphisms in the leptin receptor  of 2.0. There were a total of 209 cases and 209 controls in our study population indicating that this sample size has adequate statistical power to detect an OR of 2.0. However, when we stratify by menopausal status, the number of cases and controls become much lower, thus decreasing the statistical power of the study. For example, a sample size of 137 premenopausal cases and 137 premenopausal controls would be adequate to detect an odds ratio of 2.0 while there were 114 premenopausal cases and 121 premenopausal controls in our study. It is possible that variations in LEPR polymorphisms and other low penetrance genes may contribute to the marked worldwide variation in breast cancer incidence, with the highest age-standardized incidence rate (ASR) in North America  and the lowest age-standardized incidence rates in sub-Saharan Africa  .LEPR 223Arg allele of the LEPR Gln223Arg polymorphism of the leptin receptor gene. To the best of our knowledge, ours is the first study to provide information on the role of LEPR Gln223Arg polymorphism in breast cancer risk in sub-Saharan African women, a population characterized by paucity of epidemiological literature on the determinants of breast cancer and other malignancies.In conclusion, this study has demonstrated a modestly increased risk of premenopausal breast cancer in women harboring the LEPR: Leptin receptor; DNA: Deoxyribonucleic acid; PCR: Polymerase chain reaction; SNP: Single Nucleotide Polymorphism; RFLP: Restriction fragment length polymorphism; STAT3: Signal transducers of activation of transcription; ERK: Extracellular signal-regulated kinase; MAPK: Mitogen-activated protein kinase; SAS: Statistical analysis systemsThe authors declare that they have no competing interests.MNO, CHB, ET, SJG, REF, LHK, participated in conceptualization, design of the study and preparation of manuscript. MNO, ERE, SNA, and EEU recruited study participants from Nigeria and organized the transfer of biological samples to the University of Pittsburgh. MNO, CHB, ET, SJG and JMZ carried out the genetic analysis.The pre-publication history for this paper can be accessed here:


A cohort study of 1,150 premenopausal French women with benign breast disease diagnosed in two breast clinics between 1976 and 1979 was carried out to analyse the relationship between progestogen use and the risk of breast cancer. The follow-up accumulated 12,462 person-years. The risk of breast cancer was estimated using a Poisson regression analysis on person-time data and the proportional hazards model. In the latter analysis, cumulated progestogen use and age were considered as time-varying covariables and adjustment was performed on the main risk factors for breast cancer. Neither overall progestogen use nor the duration of use was found to be significantly associated with the risk of breast cancer. When progestogens were classified into two categories according to their hormonal potency (19-nortestosterone derivatives vs other progestogens), 19-nortestosterone derivative use was found to be significantly associated with a lower risk of breast cancer. In the adjusted model, the corresponding risk of breast cancer was 0.48 . In addition, there was a linear trend in the decrease of the relative risk of breast cancer with the duration of use (P = 0.02). These results do not support the hypothesis that progestogens might increase the breast cancer risk. They suggest, instead, that treatment with 19-nortestosterone derivatives might have a beneficial effect on the risk of breast cancer in women with benign breast disease.


However, the association between B vitamin intake and breast cancer risk in Brazilian women in particular has not yet been investigated.Several studies have determined that dietary intake of B vitamins may be associated with breast cancer risk as a result of interactions between 6, and vitamin B12 were derived from a validated Food Frequency Questionnaire (FFQ). Genotyping was completed for MTHFR A1298C and C677T, and MTR A2756G polymorphisms. A logistical regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).A case-control study was conducted in São Paulo, Brazil, with 458 age-matched pairs of Brazilian women. Energy-adjusted intakes of folate, vitamin B6, or vitamin B12 nor MTHFR polymorphisms were independently associated with breast cancer risk. Analysis stratified by menopausal status showed a significant association between placement in the highest tertile of folate intake and risk of breast cancer in premenopausal women . The MTR 2756GG genotype was associated with a higher risk of breast cancer than the 2756AA genotype , and statistically significant interactions with regard to risk were observed between the MTHFR A1298C polymorphism and folate (P = 0.024) or vitamin B6 (P = 0.043), and between the MTHFR C677T polymorphism and folate (P = 0.043) or vitamin B12 (P = 0.022).Neither dietary intake of folate, vitamin BMTHFR polymorphisms and dietary intake of folate, vitamin B6, and vitamin B12 had no overall association with breast cancer risk. However, increased risk was observed in total women with the MTR 2756GG genotype and in premenopausal women with high folate intake. These findings, as well as significant interactions between MTHFR polymorphisms and B vitamins, warrant further investigation. In another, folate leads to purine synthesis in DNA repair  and 83 Japanese-Brazilian [91%]) gave written informed consent, while among potential controls, 22 patients refused, resulting in a total of 472 matched pairs ultimately enrolled. The study was approved by the Comissão Nacional de Ética em Pesquisa (CONEP), Brasília, Brazil, and by the Institute Review Board of the National Cancer Center, Tokyo, Japan, in 2000.In-person interviews were conducted by trained interviewers using a structured questionnaire which included questions on demographic characteristics, medical history, family history of cancer, anthropometric factors, smoking habits, physical activities, menstrual and reproductive factors, as well as a self-quantitative FFQ with 118 food terms.6, and vitamin B12 [The FFQ used here, developed specifically for this study to estimate dietary intake among participants, inquired about how often participants consumed individual food items (frequency of consumption), as well as about representative relative sizes compared with standard portions in the preceding year (control patients) or one year before their breast cancer diagnosis (cancer patients). Daily food intake was calculated by multiplying frequency by standard portion size and relative size for each food item in the FFQ. Daily intake of nutrients was calculated using the United States Department of Agriculture (USDA) food composition tables  and the amin B12 . Our FFQ6, and 0.33 for vitamin B12.The validity of nutrient intake estimated from the FFQ was evaluated in a subsample of the control group. Fifty-five women completed a 4-day dietary record (DR) in two seasons. Spearman's correlation coefficient between energy-adjusted nutrient intakes estimated from the FFQ and DR was 0.30 for folate, 0.38 for vitamin B® DNA kits in accordance with the manufacturer's protocol. Genotyping of the three single-nucleotide polymorphisms (SNPs) in the MTHFR and MTR genes was performed by a commercial laboratory  using TaqMan® SNP Genotyping Assays developed by Applied Biosystems . Cases and matched controls were analyzed in the same well by laboratory personnel blinded to case-control status. To assess quality control, we conducted laboratory genotyping of six SNPs of four genes  using approximately 25% of samples from the present study, although SNPs used in the present study were not included. The concordance rates between Genetic Lab. and our laboratory varied between 97.5% and 99.2% for the six SNPs.Peripheral blood samples were obtained from each subject and stored at -80°C until analysis. Genomic DNA samples were extracted from the blood using QIAGEN FlexiGeneStudy subjects with markedly low or high total energy intake  or without DNA samples were excluded from the study, leaving 458 pairs of Brazilian women for analysis (379 non-Japanese Brazilian and 79 Japanese-Brazilian pairs). ORs and 95% CIs for associations between dietary intake, polymorphisms, and risk of breast cancer were calculated by the conditional logistical model, and statistical significance was examined by the Wald chi-square test. Baseline characteristics between cases and controls were compared by the Cochran-Mantel-Haenszel test using matched-pair strata. Deviation from the Hardy-Weinberg equilibrium in genotype frequencies was assessed with the chi-square test.6, and vitamin B12 were categorized into tertiles for total study subjects based on the distribution among controls, with the lowest tertiles considered as the reference categories.In the primary analysis of all subjects, risk factors identified by univariate analysis as independently related to disease risk, including smoking habit, alcohol consumption, number of live births, and a moderate level of physical activity in the preceding 5 years, were adjusted in multivariable analyses. Other potential confounders such as age at menarche, age at first live birth, breast feeding, number of pregnancies, and breast cancer in first-degree relatives were not independently associated with breast cancer risk, nor did they substantially modify the effects when tested in the multivariable model (less than 10% change in strength), and were thus not retained. Nutrient intakes of folate, vitamin BMTHFR 677CC and 1298AA, and MTR 2756AA were considered as the referent group. With regard to evaluation of the interactive effects of SNPs and dietary intakes on breast cancer risk, the combined effects of SNPs and dietary intakes were assessed by adding the multiplicative interaction product (genotype × dietary intake) to the final model as indicator variables.To increase statistical power, respective genotypes of less-frequent polymorphisms were also combined into two groups. Genotypes of p values reported were two-sided, and the significance level was set at p < 0.05. All analyses were conducted with SAS 9.02 .In a secondary analysis, we stratified patients by menopause status, alcohol consumption, and vitamin supplement use using an unconditional logistic model which adjusted for identified risk factors as well as age and ethnicity. Further, trend testing was conducted by treating each categorized variable as a continuous term and entering the variable into the logistic regression models. All Characteristics of case and control subjects at baseline are shown in Table 6, and vitamin B12 as reference, no statistically significant association was observed between vitamin intake and breast cancer risk in all women (Table 6 intake (P for trend = 0.047). Similarly, a statistically significant increase in risk was seen for high folate intake in premenopausal women of non-Japanese Brazilian ethnicity , but not in those of Japanese-Brazilian ethnicity.Using the lowest tertile intake of folate, vitamin BMTHFR or MTR genes and breast cancer risk are shown in Table MTR 2756GG genotype had a significantly increased risk of breast cancer , but no other statistically significant associations were observed for all, pre-, or postmenopausal women. Similar null results were found in both non-Japanese and Japanese-Brazilian women (data not shown), although distribution of the MTHFR C677T polymorphism  in control subjects differed significantly between the non-Japanese Brazilian  and Japanese-Brazilian women  (P = 0.038).Associations between polymorphisms of the MTHFR A1298C and C677T, MTHFR A1298C and MTR A2756G, and MTHFR C677T and MTR A2756G, none of which was statistically significantly associated with the risk of breast cancer compared to their wild genotypes.We also examined the effects of combined genotypes of MTHFR and MTR polymorphisms and dietary intake on breast cancer risk are shown in Table MTHFR 1298AA and 677CC and MTR 2756AA with the lowest tertiles of dietary intake were used as references, with variant allele combinations. Statistically significant positive associations between folate intake and breast cancer risk were observed among women with the MTHFR 1298AA (P for trend = 0.003), 677CT and TT (P for trend = 0.011), and MTR 2756AA genotypes (P for trend = 0.049). An increased risk of breast cancer was seen in those women with the lowest folate intake who had the MTHFR 1298AC and CC genotype . In contrast, a decreased risk was seen in those women with the lowest folate intake who had the MTHFR 677CT and TT genotype . Statistically significant interactions were detected for folate intake with MTHFR A1298C (P for interaction = 0.024) and C677T polymorphisms (P for interaction = 0.043).The joint effects of 6 intake and breast cancer risk among women with the MTHFR 1298AA genotype (P for trend = 0.061), whereas an inverse association was observed between the highest tertile of vitamin B12 intake and breast cancer risk among those with the MTHFR 677CC genotype (P for trend = 0.073). A statistically significant interaction was detected between the MTHFR A1298C polymorphism and vitamin B6 intake (P for interaction = 0.043) and between the MTHFR C677T polymorphism and vitamin B12 intake (P for interaction = 0.022).A marginally positive association was observed between the highest tertile of vitamin B6, and vitamin B12 intake and the risk of breast cancer. These findings are consistent with previous studies on folate [6 [12 [In this study, we found no overall association between folate, vitamin Bn folate ,28,33-40olate [6 ,39,40, ae [6 [12 ,28,39,40Generally, folate is able to prevent the development of tumors before preneoplastic lesions have been established, but conversely increases tumorigenesis once lesions have been established ,41,42. A6 intake was associated with an increased risk of breast cancer, but did not indicate the menopausal status of participants [6 [6 intake may thus be due to chance.Similarly, a study on plasma folate found that concentration was associated with an increase in breast cancer risk in premenopausal but not in postmenopausal women . This sticipants . In contpants [6 . Our finA Canadian study found that a high total folate intake, obtained mainly from nutritional supplements, significantly increased breast cancer risk by 32% (highest >853 μg/day versus lowest quintile ≤336 μg/day) in postmenopausal women . HoweverMTHFR C677T polymorphism and breast cancer risk in Caucasians and East Asians, or between the MTHFR A1298C polymorphism and risk in Caucasians [MTHFR 677CT and TT genotype compared to those with the CC genotype, we did not observe any increase in risk in these groups. Further, contrary to the findings in a previous study conducted in Americans [MTHFR A1298C and C677T. This lack of concordance in findings may be due to the low proportion of the MTHFR 677T genotype in our study population or to compensation by the folate-replete status of patients for the effects of the variant alleles of the MTHFR A1298C and C677T genotypes [A recent meta-analysis indicated no overall significant association between the ucasians . Our stuucasians ,43. In cucasians , howeverMTR gene contributes to alterations in the plasma levels of homocysteine and folate; specifically, subjects with the 2756AG and GG genotypes have lower levels of plasma homocysteine or higher levels of serum folate than those with the 2756AA genotype [MTR A2756G and a decreased risk of breast cancer [MTR A2756G polymorphism and other genetic polymorphisms, or to the interaction between the MTR A2756G polymorphism and other genetic polymorphisms related to folate metabolism, such as that for methionine synthase reductase (MTRR G66A) [cSHMT C1420T) [MTHFR C677T [MTR A2756G and either MTHFR A1298C or C667T and breast cancer risk, nor could we test the joint effects of MTR with MTRR or cSHMT genes since MTRR and cSHMT genes were not available in the present study. Given the low frequency of the MTR 2756GG genotype in our study population, the significant finding of our present study may be the result of chance.The genotype ,45. Whengenotype . A Polist cancer . This obRR G66A) ,45, cyto C1420T) , or MTHFFR C677T . HoweverMTHFR polymorphism may be elicited to show that (a) the lower activity of variant genotypes may increase the risk of breast cancer at low levels of dietary folate since less 5-methyl THF is made available for DNA methylation, and (b) variant genotypes might provide advantages over the wild genotype in folate-replete conditions since 5,10-methyl THF would be available for nucleotide synthesis [MTHFR 1298AC and CC genotype. Contrary to (a), however, we also saw a decrease in breast cancer risk among women with the lowest folate intake who had the MTHFR 677CT and TT genotype. Similar findings of decreased breast cancer risk in variant MTHFR C677T genotypes have been reported in previous studies in German [MTHFR C677T polymorphism was speculated to increase the pool of intracellular 5,10-methylene THF, which protects against potential defects in DNA synthesis, although circulating folate levels (5-methyl THF) tended to be lower [MTHFR 1298AA and MTR 2756AA genotype in a higher tertile of folate intake may be due to the harmful effects brought about by excessive intake of folate. Notion (b) suggests that the lower activity of variant alleles of MTHFR A1298C provides advantages over the MTHFR 1298AA genotype, but with the compensation of sufficient folate intake, the lower enzyme activity was attenuated to result in the lack of significant association seen with the variant MTHFR A1298C genotypes in the higher category of folate intake. In addition, the observed trend to a decline in breast cancer risk with increased vitamin B12 intake (P for trend = 0.073) and significant interaction between vitamin B12 and MTHFR C677T polymorphism might be due to the function of vitamin B12 as a cofactor in folate metabolisms [Previous authors have speculated that interactions between folate and ynthesis ,4. Suppon German , and Chibe lower , backgrobe lower ,37, or pabolisms .6, and vitamin B12 was assessed after breast cancer diagnosis and was therefore sensitive to recall bias. Case subjects may have been more motivated to recall diet than controls, and their recall may also have been inaccurate, depending on the belief of an association between diet and their disease. Second, although substantially high participation rates among both eligible case and control subjects minimized potential selection bias, the use of cancer-free patients as controls, whose dietary habits may have differed from the general population due to health consciousness or disease concerns, might have lead to selection bias. Third, as our subjects were recruited from eight hospitals in São Paulo, Brazil, they may not necessarily be representative of the general Brazilian population, and thus any extrapolation of results to the general population should be done cautiously. Fourth, our validation study found relatively low correlation coefficients between FFQ and DR-based nutrient intake estimates. Further, the validation study indicated that measurement errors in assessing nutrient intake by FFQ were unavoidable, although such random errors tend to result in null associations [Several limitations of this study warrant mention. First, dietary intake of folate, vitamin Bciations . Fifth, 6, and vitamin B12, MTHFR genotype, and breast cancer risk. However, we did identify an increased risk of breast cancer in total women with the MTR 2756GG genotype, increased risk associated with higher folate intake in premenopausal women, and gene-nutrient interactions. Further studies into these factors will help to elucidate the etiology of breast cancer.In this case-control study conducted in Brazilian women, we found no overall significant associations between dietary intake of folate, vitamin BCI: confidence interval; FFQ: food frequency questionnaire; MTHFR: 5,10-methylenetetrahydrofolate reductase; MTR: methionine synthase; OR: odds ratio; SNPs: single-nucleotide polymorphisms.The authors declare that they have no competing interests.EM performed the data analysis and drafted the manuscript. MI participated in the study design, coordinated the study and helped with data integrity, analysis, interpretation, and preparation of the manuscript. JI participated in data analysis and interpretation of data. GH involved the study design, supervised the study, contributed to data acquisition and interpretation. IN involved the study design, and contributed to data acquisition and interpretation. SC contributed to data acquisition and interpretation. JM contributed to data acquisition and interpretation. FL contributed to data acquisition and interpretation. ST designed, supervised and coordinated the study and helped with data interpretation and preparation of the manuscript. All authors have read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2407/9/122/prepub


Using a model-based approach, we estimated the probability that an individual, with a specified combination of risk factors, would develop lung cancer within a 5-year period.Data from 579 lung cancer cases and 1157 age- and sex-matched population-based controls were available for this analysis. Significant risk factors were fitted into multivariate conditional logistic regression models. The final multivariate model was combined with age-standardised lung cancer incidence data to calculate absolute risk estimates.Combinations of lifestyle risk factors were modelled to create risk profiles. For example, a 77-year-old male non-smoker, with a family history of lung cancer (early onset) and occupational exposure to asbestos has an absolute risk of 3.17% . Choosing a 2.5% cutoff to trigger increased surveillance, gave a sensitivity of 0.62 and specificity of 0.70, while a 6.0% cutoff gave a sensitivity of 0.34 and specificity of 0.90. A 10-fold cross validation produced an AUC statistic of 0.70, indicating good discrimination.If independent validation studies confirm these results, the LLP risk models’ application as the first stage in an early detection strategy is a logical evolution in patient care. In addition, being the most common cancer with over 1.3 million incident cases per year, lung cancer has the highest worldwide rate of cancer mortality  . Two population controls per case were selected from registers of general practitioners in Liverpool and matched to lung cancer cases by year of birth (±2 years) and gender.A standardised lifestyle questionnaire was used to collect detailed information on socioeconomic and demographic characteristics, medical history, family history of cancer, history of tobacco consumption and lifetime occupational history. Extensive information about tobacco smoking was elicited for all participants including smoking status, inhalation, type of cigarette smoked, number of cigarettes smoked per day, age at start and end. An ever smoker was defined as someone who had smoked at least 100 cigarettes in their lifetime and a current smoker was defined as a participant who reported smoking 2 years prior to the date of the interview. During the interview, all periods of consumption were defined and counted towards total exposure.Information on history of cancer among first degree relatives  was recorded, including age of diagnosis, site of cancer and relation to the participant. All participants were asked if they had ever been told by a physician that they had a prior non-malignant lung disease such as asthma, bronchitis, emphysema, pneumonia or tuberculosis at any age at least 2 years before any diagnosis of lung cancer (or date of interview for controls). Furthermore, if participants had ever been diagnosed with a malignant tumour, the primary site was recorded, and their age at the time of diagnosis.The methodology to assess occupational exposure was based on that used by The study protocol was approved by the Liverpool Research Ethic Committee and all research participants provided written, informed consent in accordance with the Declaration of Helsinki.χ2 test. Differences between cases and controls in age and self-reported pack-years were tested using the Student's t-test. When the data distribution significantly deviated from normal, the Wilcoxon rank sum test was performed. The risk model was developed using conditional logistic regression. The multivariate model was built up in two phases. First, all statistically significant covariates (P<0.05) in univariate analyses were included in a multivariate model, and backward stepwise regression was performed, whereby those factors losing their significance (P>0.05) in the multivariate analysis were dropped. Those factors not significant in the univariate analyses were subsequently fitted to the multivariate model, with adjustment for the remaining significant effects, to detect effects, which are only seen when the major risk factors are accounted for. Pairwise interaction tests were conducted between all the risk factors in the final multivariate model to ensure that they did not modify each other's effects. Once the final multivariate model was determined, the logistic model was converted to absolute risk using the method described in the Distributions in demographic variables between cases and controls were evaluated by the P=0.04), prior diagnosis of pneumonia (P=0.001), occupational exposure to asbestos (P<0.0001) and prior diagnosis of a malignant tumour (P<0.0001).Five hundred and seventy-nine incident cases of lung cancer and 1157 population controls were recruited between 1998 and 2005. Overall, the response rate was 58.3% for cases and 61.5% for controls. Caucasians represented approximately 99% of both the cases and the controls. The majority of lung cancer cases in the study population presented with non small cell lung cancer (83.2%). vs none) of lung cancer in the study population overall or in late-onset cases, regardless of the age of affected relatives. There was, however, a substantial and statistically significant increase in risk where both the lung cancer case and the affected relative were diagnosed with lung cancer before the age of 60 years . Significantly elevated odds ratios were also observed in connection with an affected relative diagnosed before age 60 regardless of age-at-onset of the case  (P<0.0001), smoking duration (P<0.0001) and smoking pack-years (P<0.0001). No association was found between smoking pipes or cigars and risk of lung cancer. A significant increase in risk was observed for those who reported ever exposure to spousal tobacco smoke . A significant dose–response effect was observed with duration of exposure (P=0.01), with the largest increase in risk in the highest exposed group corresponding to more than 50 years of exposure . A nonsignificant excess risk was observed for ever exposure to secondhand smoke in the workplace . However, when analysed by duration of exposure, a dose–response effect was not observed (P=0.83). There was no evidence of elevated risk of lung cancer due to exposure to secondhand smoke from social sources. The high lifetime exposure prevalence to asbestos seen in this study is manifest as an overall risk of 1.88 , which was reduced after adjustment for occupational confounders to 1.51 (95% CI: 1.02–2.04).No significant effect of marital status, education or socioeconomic status was observed on lung cancer risk after adjustment for smoking. There was a significant increase in risk amongst individuals with a prior diagnosis of pneumonia both before (odds ratio (OR)=1.62, 95% confidence interval (CI): 1.21–2.17) and after adjustment for smoking . Participants with a prior diagnosis of emphysema had a significant increase in risk before adjustment  but not after . No effect was present for prior asthma, bronchitis and tuberculosis. Sex-specific analyses indicated that the risk of lung cancer remained significantly elevated for males who had a prior diagnosis of pneumonia , but not for females . Women who had a prior diagnosis of emphysema exhibited a significantly increased lung cancer risk , which was not observed in males . Physician-diagnosed prior cancer was associated with a significantly increased lung cancer risk  after adjustment for age, sex and smoking. The majority of reported previous cancers were cancers of the skin, which were associated with a 2.2-fold increased lung cancer risk (95% CI: 1.12–4.26) followed by cancers of the breast . Although there was a significant trend of increasing risk with numbers of affected relatives, there was no significant effect of family history (any P=0.01), prior diagnosis of pneumonia (P=0.002), prior diagnosis of cancer other than lung (P=0.005), occupational exposure to asbestos (P<0.001) and duration of smoking (P<0.001). We observed significant interaction between a prior diagnosis of pneumonia and prior diagnosis of malignant tumour (P=0.04), which lost significance when adjusted for other risk factors in the multivariate model (P=0.07). Although various measures of smoking were significant in the univariate analysis, only duration of smoking remained significant in the multivariate model. An association between a prior diagnosis of emphysema and lung cancer also lost significance in the multivariate model.The final multivariate logistic regression model is presented in Using the methods described in the The LLP risk model estimates also illustrate how a substantial risk can be conferred by risk factors other than smoking. Consider a 67-year-old man who has never smoked, but who has a family history of lung cancer (with the affected relative aged under 60 at diagnosis), a history of asbestos exposure and a prior diagnosis of cancer. His estimated risk in the next 5 years is 3.16%. A man of the same age without these three risk factors would have a 5-year risk of 0.43%. The population or baseline risk in UK males of this age (including those with and without risk factors) as calculated from National Statistics  is approBy combining case–control data with regional incidence rates, we have developed a model to project individual 5-year absolute risks of developing lung cancer. The model has the potential to identify high-risk individuals by focusing on information that can be readily obtained in the primary care setting. The LLP risk model also appears to discriminate between high and low risk, although it will require rigorous validation in separate populations. As well as accounting for the three most important risk factors for lung cancer: age, sex and smoking, the LLP risk model incorporates other important disease risk factors such as family history of lung cancer, occupational exposure to asbestos, prior diagnosis of pneumonia and prior diagnosis of a malignant tumour other than lung cancer.Similar to previously well-conducted cohort studies (Sensitivity and specificity of the LLP risk model compares favourably with previous lung cancer absolute risk models developed by An obvious strength of this study is that detailed information on the main risk factors such as active smoking, family history of lung cancer and occupational exposure was ascertained by closely supervised, trained interviewers using standardised questionnaires. No proxy interviews were performed. All cases had histologically or cytologically confirmed primary lung tumours. In common with all risk prediction models, the LLP risk model has several limitations. First, the absolute risks estimated for each combination of risk factors are based on relative risks derived from a case–control study. In this study, cases were individuals with newly diagnosed lung cancer identified by surveillance of all the hospitals responsible for the treatment of lung cancer in Liverpool and, after matching for age and sex, controls were selected from population lists that were essentially complete. Thus, cases and controls were both drawn from the same underlying population. However, the refusal rates were high, 42% among cases and 39% among controls. Given that these data did not permit description of smoking patterns of cases and controls refusing to participate, one cannot exclude that the lifestyle characteristics of nonparticipants may differ from the participants leading to an under- or overestimation of the true relative risks. There is also the potential that recall and other information biases could influence our results, as cases and controls were asked to report their lifestyle habits and behaviours for many years prior to interview. For these reasons, it is important that independent validation data be obtained to assess the relative risk features and absolute risk projections from this model. The limitations notwithstanding, this study can inform the debate about the best approach to select individuals at high risk of lung cancer for surveillance or prevention programmes.Numerous nonrandomised studies have demonstrated that lung cancer can be diagnosed at a significantly earlier stage with CT screening than in current clinical practice (Although some of the absolute risk estimates may seem rather high, they are consistent with population incidence. In the penultimate example in Although the results suggest that the LLP risk model may be useful for predicting risk, more work is needed to test the applicability of the model in diverse populations, including those from diverse geographic regions. It is clear that some populations, for example, African Americans, have risk factors other than those in our model (Although several issues concerning lung cancer risk prediction have been highlighted, we believe that its application as the first stage in an early detection strategy is a logical evolution in patient care. The results presented in this paper suggest that the LLP risk model could predict approximately two-thirds of lung cancer within 5-years, screening only 30% of the population. If resources were limited or the intervention carried such adverse effects as to require a very high-risk population to have a strong benefit–harm balance, a subset of 10% of the population could be identified in which 34% of the cases would arise. The effect of restricting screening to a subpopulation of high-risk individuals will markedly reduce the cost of screening programmes at the expense of missing a proportion of lung cancers in individuals below the cutoff. This ‘high-risk strategy’ aims to help individuals with the greatest need of, and the potential to benefit from early detection. Such stratification on the basis of efficiency implies the difficult decision of where to place the cutoff, but the issue must be addressed nonetheless. It is likely that identifiable genetic susceptibility will, in the future, constitute an important factor in the selection of a more tightly defined risk group. In the meantime, it is appropriate to use a risk prediction model such as ours to identify a high-risk group for CT screening, so long as the results are not used to make inferences about a screening strategy in the general population (


Sir,The Collaborative Group on Hormonal Factors in Breast Cancer has certainly done a disservice regarding the question of the possible connection between tobacco smoke and breast cancer by publishing their recent paper  and concAn estimate of the magnitude of the passive smoking breast cancer risk and its effect on the active smoking risk can be obtained by studying the data in


Serum IGFBP-3 was associated with a reduction in risk in premenopausal women after adjustment for IGF-I . Neither IGF-I nor IGFBP-3 was associated with risk in postmenopausal women and serum IGF-II concentration was not associated with risk in pre- or postmenopausal women. These data are compatible with the hypothesis that premenopausal women with a relatively high circulating concentration of IGF-I and low IGFBP-3 are at an increased risk of developing breast cancer.The associations between serum concentrations of insulin-like growth factor-I (IGF-I), IGF-II and IGF-binding proteins (IGFBP)-3 and risk of breast cancer were investigated in a nested case–control study involving 117 cases  and 350 matched controls within a cohort of women from the island of Guernsey, UK. Women using exogenous hormones at the time of blood collection were excluded. Premenopausal women in the top  It is well established that insulin-like growth factor-I (IGF-I) and IGF-II can stimulate cell proliferation and inhibit cell death in many tissue types  includinThere is considerable between-person variation in the circulating concentrations of IGF-I, IGF-II and their binding proteins, believed to be due to genetic and environmental factors , and new volunteers were also sought. Study participants completed a questionnaire at interview containing details of personal characteristics and reproductive history. Height and weight measurements were taken and a nonfasting blood sample was collected. Serum was stored in 2 ml aliquots at −20°C until analysis. All participants gave voluntary written informed consent for the use of their questionnaire data and blood samples for research purposes.Follow-up was through pathology reports , Guernsey death certificates and the Wessex cancer registry. A woman was eligible for this study if she was not using any exogenous sex hormones at the time of blood collection and if she had not previously been diagnosed with cancer other than nonmelanoma skin cancer. Women who were premenopausal at recruitment were eligible if they reported that they were menstruating in their usual pattern and if their cycle length was not longer than 42 days. Postmenopausal women were eligible if they reported that they were naturally postmenopausal at the time of recruitment  or if they had undergone a hysterectomy without bilateral oophorectomy before menopause and were over 60 years old at recruitment.Cases were women diagnosed with breast cancer up until the end of November 2000. Controls were women who were alive and free of breast cancer at the time of a case's diagnosis and who matched each case according to: age (within 2 years), date of blood collection (within 1 year) and menopausal status . Cases who stated they were premenopausal at recruitment were also matched on the day of menstrual cycle . Postmenopausal cases were matched to controls according to whether or not they had had a hysterectomy; and, for naturally postmenopausal cases, the number of years since menopause (1–2 years or 3+ years). Where it was not possible to match a postmenopausal case who had had a hysterectomy, controls who had been naturally postmenopausal for 3 or more years were identified. Three control subjects were randomly selected from all those who were suitably matched, except for one premenopausal case where only two controls were available. Once a control was matched to a case, she was unavailable for matching with further cases.In total, 193 eligible breast cancer cases were identified during the follow-up period. In all, 76 cases were subsequently excluded because of insufficient sera, leaving 117 cases  and 350 controls for analysis .−1, respectively, for samples from the first phase of recruitment and 15.7, 131 and 159 nmol l−1, respectively, for samples from the second phase of recruitment. To minimise the impact of these differences on the estimates of odds ratios (OR), we categorised women into thirds based on the distribution among controls in their phase of recruitment.Serum samples for all study participants were shipped on dry ice to the Division of Surgery, Bristol Royal Infirmary, UK for measurement of serum IGF-I, IGF-II and IGFBP-3. Individually matched cases and controls were analysed in the same laboratory batch and personnel were blinded as to the case–control status of samples. Double-antibody enzyme-linked immunosorbant (ELISA) assays were used to measure IGF-I  and IGF-II . Assays for serum IGFBP-3 were carried out using a previously validated in-house double antibody radioimmunoassay . Adjustment for the following potential confounding factors was made, in addition to those controlled for by matching: body mass index (BMI) , age at menarche  and age at first birth . Additional adjustment for IGF-I or IGFBP-3  was made where appropriate. The associations of the molar ratios of IGF-I/IGFBP-3 and IGF-II/IGFBP-3 with breast cancer risk were also examined. Odds ratios for each third were calculated using the lowest third as the reference category. Where appropriate, a test for linear trend was performed to assess statistical significance across exposure categories by scoring each third as 1, 2 and 3. All P-values were based on two-sided tests; a value of less than 0.05 was considered statistically significant. The statistical package R was used for all analyses  and with IGFBP-3 . IGF-II was also strongly positively correlated with IGFBP-3 . IGF-I was inversely related to age, but no significant associations were found between peptide concentrations and characteristics such as BMI, smoking, parity, age at menarche, age at first birth or age at menopause in either pre- or postmenopausal women (data not shown).The correlations of the three peptide measures with each other and with other factors were examined in controls. Serum IGF-I was positively correlated with serum IGF-II (age-adjusted Spearman's rank correlation coefficient P=0.21). The association between the molar ratio of IGF-I/IGFBP-3 and breast cancer risk was similar to that of IGF-I adjusted for IGFBP-3 . Serum IGFBP-3 concentration was associated with a reduction in risk, which was strengthened after statistical adjustment for BMI, age at menarche and age at first birth  for the highest vs the lowest third; test for linear trend; P=0.02). This association remained but was not statistically significant after additional statistical adjustment for serum IGF-I concentration . There was no association between serum IGF-II concentration and risk in premenopausal women, either before or after statistical adjustment for IGFBP-3 ( IGFBP-3 , and no For postmenopausal women, serum concentrations of IGF-I, IGF-II and IGFBP-3 were not associated with breast cancer risk either before or after statistical adjustment for potential confounding factors .The findings from this small prospective study are consistent with a moderate increase in breast cancer risk associated with high levels of IGF-I, after adjustment for IGFBP-3. This is broadly consistent with previous prospective studies that have found IGF-I, as absolute concentrations or relative to IGFBP-3, to be predictive of breast cancer risk in premenopausal women (Our data also show that a relatively high circulating IGFBP-3 concentration is associated with a reduction in risk in pre-, but not postmenopausal women. Although our findings are consistent with the nonsignificant inverse association reported in one previous prospective study . In addiIn this study, adjusting for IGFBP-3 increased the OR for the association of IGF-I with premenopausal cancers. There is considerable controversy in the literature regarding measurements of IGFBP-3. Several commentaries have noted that measurements of IGFBP-3 are still hampered by technical problems, particularly in relation to standardisation of assays. It is now evident that there is considerable heterogeneity in the forms of IGFBP-3. In addition to major differences in glycosylation and proteolytic modification, it is clear that there are many other post-translationally modified forms present in the circulation. The heterogeneity of the protein presents a considerable challenge for assay calibration. The various reports of strong and sometimes conflicting associations between IGFBP-3 concentrations and cancer risk indicate that it would be of considerable interest to measure individual forms of IGFBP-3. At present, there are no assays that can reliably measure specific characterised isoforms of IGFBP-3 and these isoforms can only really be assessed by electrophoretic techniques that are not easily applied to epidemiological studies.Our finding of a lack of association between postmenopausal circulating levels of IGF-I and IGFBP-3 with subsequent breast cancer risk, albeit based on only 47 breast cancer cases, are also consistent with those reported by most other prospective studies, although the recent study of in vitro (This is the first study to examine prospectively the association between serum IGF-II concentration and breast cancer risk in premenopausal women. Although IGF-II has a clearly established role in foetal development (The main strengths of this study are the prospective design with cases and controls matched according to predefined established risk factors for breast cancer. In addition, blood samples were taken at least 3 years before cancer diagnosis, thereby reducing the possibility that differences in IGF levels are a result of an undiagnosed breast tumour at the time of blood collection. Although peptide measurements were made in a single blood sample from each woman, previous studies suggest that this reliably reflects long-term IGF-I and IGFBP-3 levels in adult women, with intraclass correlation coefficients between 0.73 and 0.87 for samples taken a year apart . NeverthIn summary, the results of this prospective study are consistent with the hypothesis that premenopausal women with a relatively high circulating concentration of IGF-I and low IGFBP-3 are at an increased risk of developing breast cancer.


P<0.001). However, younger female carriers (<50 years) showed a rise in cancer-related worry 1 month post-testing (P<0.05). This returned to pre-testing baseline levels 12 months later, but worry remained significantly higher than noncarriers throughout (P<0.01). There were no significant differences in GHQ scores between males and females (both carriers and noncarriers) at any time point. Female carriers engaged in significantly more risk management strategies than noncarriers in the year following testing . In the 12 months post-testing, 28% carriers had bilateral risk-reducing mastectomy and 31% oophorectomy. Oophorectomy was confined to older (mean 41 yrs) women who already had children. However, worry about cancer was not assuaged by surgery following genetic testing, and this requires further investigation. In all, 20% of female carriers reported insurance problems. The data show persistent worry in younger female gene carriers and confirm changes in risk management consistent with carrier status. Men were not adversely affected by genetic testing in terms of their general mental health.This multi-centre UK study assesses the impact of predictive testing for breast and ovarian cancer predisposition genes (BRCA1/2) in the clinical context. In the year following predictive testing, 261 adults  from nine UK genetics centres participated; 91 gene mutation carriers and 170 noncarriers. Self-report questionnaires were completed at baseline (pre-genetic testing) and 1, 4 and 12 months following the genetic test result. Men were assessed for general mental health ) and women for general mental health, cancer-related worry, intrusive and avoidant thoughts, perception of risk and risk management behaviour. Main comparisons were between female carriers and noncarriers on all measures and men and women for general mental health. Female noncarriers benefited psychologically, with significant reductions in cancer-related worry following testing ( Following the identification of two predisposition genes (BRCA1 and BRCA2) that increase the risk of breast and/or ovarian cancer  . The present study includes men and women unaffected by cancer (i.e. no diagnosed cancer) attending nine centres that currently undertake the majority of BRCA1/2 testing in clinical cohorts in the UK. The study aims to document any psychological morbidity related to genetic testing, ascertain cancer risk perceptions and examine the ongoing risk management in BRCA1/2 carriers and noncarriers in the year following genetic testing. Clarifying whether insurance discrimination has been experienced as a result of genetic testing is a further aim. Comparisons will be made between carriers and noncarriers, men and women. Three key questions are addressed:What mental health problems exist in men and women and how are they affected both short and long term by BRCA1/2 genetic testing?Do female participants understand their risks of developing cancer following genetic testing?How does BRCA1/2 genetic testing impact upon risk management for women?Participants were unaffected by breast or ovarian cancer at the time of study entry, from families with an identified BRCA1/2 mutation, and a 50% (25% if an intervening relative had died) risk of inheriting a BRCA1/2 mutation. Three individuals declined participation, six declined genetic testing following genetic counselling and did not receive baseline questionnaires, nine did not return the study questionnaire, leaving a total of 298 out of 315 (97%) with completed baseline questionnaires .Using a prospective design, adults from nine clinical genetic centres participated. Trent multi-centre research ethics committee and all local research ethics committees approved the study. The consultant geneticist or genetic associate/nurse recruited participants via clinics between 1996 and 2000. Study entry followed the genetic counselling consultation prior to the consultation at which blood was drawn for genetic analysis. Written consent was obtained.The baseline questionnaire, given at the clinic prior to genetic testing, was returned directly to the data management centre at the Institute of Cancer Research, UK. These baseline data are reported in detail elsewhere  was assessed on a three-point scale (‘Not very likely’ to ‘Very likely’) or as a stated percentage or odds ratio. Knowledge of general population risk for breast/ovarian cancer was assessed. At baseline and 1-month follow-up, the perceived risk relative to the general population was rated on a five-point scale (‘Very much lower than average’ to ‘Very much higher’). At 1 and 12 months, women were asked ‘What risk figure have you been given for developing breast/ovarian cancer?’, with six response options . Men were asked if they felt that they were at increased risk of developing cancer (12-month follow-up only).Women reported on the uptake of risk management options since their genetic test, including mammography, Tamoxifen use, bilateral risk-reducing mastectomy (BRMx), bilateral risk-reducing oophorectomy (BROx), ovarian ultrasound (Ov US), clinical examination of the breasts by a doctor (CBE), breast self-examination (BrSE) or any other screening for cancer. Frequencies of BrSE and breast/ovarian biopsy rates were recorded.At all follow-ups, data were collected on number of GP visits since genetic testing to discuss the result or test-related concerns, and rates of medication for depression, worry or sleeplessness.Information was requested on any difficulties with life or health insurance following their genetic test at 12 months. Participants were not asked if they had declared the test result to their insurer.χ2 test, with Yates correction where appropriate. For ordered categorical variables, the Mann–Whitney test for trend was used. Age was analysed as a continuous variable and, in addition, participants were divided into three age groups  chosen to reflect the variations that might occur in risk management in these age groups especially in relation to screening by mammography. Women under 35 years are unlikely to receive a mammogram and women over 50 years receive regular mammograms as part of the UK National Screening Programme. Where the <35 and 35–49 year age groups behave in a similar fashion compared to the >50s, the two younger groups are reported as one (<50). Scores from the GHQ28, IES and CWS-R are treated as continuous variables. Normality is tested using the Kolmogorov–Smirnov statistic and all scores are shown to be non-normally distributed. Scores are summarised using median and range. Differences between groups  were assessed using the Kruskal–Wallis (KW) test. Changes from baseline were assessed by the signed rank test. Owing to the relative invariance of the median, the mean scores are used in the figures. Participants with missing data are omitted from the respective analyses.The association between categorical variables is examined using Fisher's exact test or the A total of 298 individuals completed baseline questionnaires (including genetic test decliners) and 285 received a genetic test result and follow-up questionnaires; 100 (35%) carriers and 185 (65%) noncarriers. In all, 261 participants (92%) returned follow-up questionnaires overall; 91 (35%) carriers and 170 (65%) noncarriers. A total of 228 (80%) completed questionnaires were returned at 1 month , 242 (85%) at 4 months (four were not sent due to administrative error) and 235 (82%) at 12 months. The proportion of carriers and male participants at baseline was the same for responders at follow-up. There were no differences between responders and nonresponders in terms of baseline demographics or psychosocial characteristics. Data for individuals who declined genetic testing at the time of study entry are reported elsewhere (N=59) at follow-up were male, 84% married or cohabiting, 41% college or university educated, and most men (73%) and women (67%) were currently employed. The median age for women was 41 (23–72 years) and 50 (22–86 years) for men. In all, 45 women and 10 men were <35 years; 107 women and 18 men were 35–49 years; 48 women and 31 men were ⩾50 years. Among gene carriers, 19 females and six males were <35 years, 42 females and nine males were 35–49, and five females and 10 males were ≥50. Most had children (87%) and the median age of offspring was 19 years (0–50 years). Altogether, 85% described themselves as Caucasian; 67% of the women and 58% of the men were noncarriers. Of the 91 carriers, 64 (70%) had BRCA1, 26 (29%) BRCA2 and one (1%) both BRCA1 and BRCA2 genetic faults.In all, 23% (P=0.06). Participants (n=47) from the six smaller centres are younger (P<0.005).Participants at each centre (responding at follow-up) were compared on demographic variables. Three centres  accounted for 82% of the participants; two smaller centres recruited only women (Cambridge and Birmingham). There were no differences in comparisons across the three larger centres, except that the London/Sutton patients had a marginally higher level of educational achievement than those from Southampton .There were no baseline differences between carriers and noncarriers on mental health measures  or noncarriers .There were no significant changes from baseline in GHQ scores in male carriers  P=0.009) and 4 (1 (0 : 20) vs 0 (0 : 22) P=0.005) months, but not at 12 months (0 (0 : 20) vs 0 (0 : 25) P=0.4), and had higher GHQ scores at 1 (0 (−8 : +18), P=0.02) and 4 months (0 (−18 : +19), P= 0.02) compared to baseline, but this had returned to baseline levels at 1 year (0 (−15 : +23), P=0.6). This increase was only significant in the 35–49 age group at 1 month (0 (−4 : +18); P=0.02). Low numbers may be the reason for not seeing a difference in the over 50 group, where there were only five carriers  vs 9 (( : 20) P<0.001; 4 months: 11 (6 : 21) vs 9 (6 : 16), P<0.001; 1 year: 10 (6 : 22) vs 9 (6 : 16), P=0.003). There was an increase in worry for carriers at 1 month (+1 (−10 : +13), P=0.001) compared to baseline and a decrease at all time points in noncarriers (1 month: −2 (−13 : +6), P<0.001; 4 months: −2 (−12 : +3), P<0.001; 1 year: −2 (−14 : +5), P<0.001). At 1 month after genetic test result disclosure, cancer worry in carriers was higher in the younger age groups (<35: 13 (6 : 19); 35–49: 13 (7 : 21)) than in the ⩾50 group (9.5 (7 : 11)) P=0.03), but this age effect was not significant at 1 year. Among noncarriers, the reduction in cancer worry was greater at each time point in the younger age group (<50) (1 month: −2 (−13 : +6) vs 0 (−8 : +3), P=0.001; 4 months: −3 (−12 : +3) vs −2 (−8 : +3), P=0.001; 1 year: −3 (−14 : +4) vs −1 (−8 : +5), P<0.001). In all, 39, 24 and 18% of female carriers worried about developing cancer ‘frequently’ or ‘constantly’ at 1, 4 and 12 months, respectively, compared to just 5, 7 and 5% of noncarriers . Also, 22, 20 and 10% said that their worry was a ‘definite’ or ‘severe’ problem at all time points compared with 3, 2 and 2% of noncarriers (P<0.01).Carriers reported  and intrusive thoughts . Gene carriers showed no significant increase from baseline in avoidant thoughts, but there was an increase in intrusive thoughts at 1 month only compared to baseline (P<0.001).There was a significant difference between carriers and noncarriers at all follow-up points for avoidant , nine (3) had taken medication for depression, seven (10) for worry, four (3) for sleeplessness and one (1) for unspecified reasons.P=0.4; ovarian cancer P=0.5; MWTrend). By 1 month follow-up, risk perception is lower in noncarriers and higher in gene mutation carriers compared to baseline  in line with their carrier status. Scheduled BROx post-testing in the gene carriers has the effect of lessening the increased risk perception  when measured 1 month following disclosure of the test result.At baseline, most women thought that they were at a higher than average risk of breast (88%) and ovarian cancer (69%).  There was no difference between carriers and non-carriers at baseline  said that they had a less than average risk, two thought they had a slightly higher than average risk, one woman thought she was at high risk. Among carriers, most (71%) thought that they had an 85% chance of developing breast cancer. All other carriers thought they were at increased risk. No carriers thought that they had an average or less than average risk. When asked at baseline if they felt at increased risk of developing other cancers, 25 female carriers said they had an increased risk of gastro-intestinal cancer, nine lung cancer, five cervical/endometrial and 10 other cancers of unspecified type. Nine male carriers said they were at increased risk of gastro-intestinal cancer, two lung cancer, 13 prostate cancer and three unspecified cancers.Two women had BRMx (both noncarriers) and 24 BROx (five gene carriers and 19 noncarriers) prior to genetic testing.P<0.01). There was marginal evidence that those having BROx were older; mean age 41 years (range 29–59) vs 37 (range 25–64) (P=0.06). There were no BRMxs during the year following predictive testing in noncarriers, but 17 (28%) gene carriers had this surgery post-genetic testing. All of these women were <50 years and four were aged <35. The rate of BRMx among gene carriers varied from centre to centre; 42% (10 out of 24) of Manchester patients, 36% (four out of 11) of Royal Marsden Hospital patients, 7% (one out of 14) of Southampton patients and 13% (two out of 15) elsewhere. Six women had both BROx and BRMx. There was no evidence that having risk-reducing surgery (N=30) reduced the levels of cancer worry, avoidant or intrusive  thoughts in gene carriers by 12 months follow-up. The numbers are small and this effect should be interpreted with caution.Three women identified as noncarriers subsequently remained in the Tamoxifen chemoprevention trial (IBIS 1 2003) compared to two carriers.P<0.001) between carriers (92%) and noncarriers (30%) at 12 months, where there had previously been no difference at baseline (P>1). Noncarriers who were older (⩾50) were marginally more likely to have had a mammogram since their test result than younger women , since they would be included in the national screening programme and continue to have increased risk due to age. There were no other age differences.Rates of mammography were significantly different  and ovarian US . There were no differences in risk management options undertaken by BRCA1 and BRCA2 carriers.A similar effect was noted for rates of CBE . Not surprisingly, carriers who had a breast biopsy during the year (three patients) had an increase in cancer worry (P=0.03).These changes in risk management are all in the expected direction, with a reduction for noncarriers at 12 months follow-up. There was no evidence that risk management uptake reduced cancer worry at 1 year (P=0.5). At 1 year, 91% of carriers and 84% of noncarriers reported practising BrSE (P=0.02). Since almost all women reported practising BrSE, it is not possible to demonstrate a relationship with cancer worry. In total, 29% of women reported increased frequency of BrSE following testing, with no difference between carriers and noncarriers ; 26% of women reported that they had decreased the frequency of BrSE and this was more common among noncarriers than carriers . Breast self-examination is recommended on a monthly basis. Most carriers reported performing BrSE monthly (33%) or more frequently (39%). However, 18% of carriers performed BrSE less frequently and 10% never. In comparison, 36% of noncarriers reported performing BrSE monthly, 21% more frequently, 27% less frequently and 16% never. At 1 year, 80% of gene carriers and 62% of noncarriers had read leaflets on breast awareness (P=0.02). Most women  had been shown how to examine their breasts.In all, 87% of women reported practising BrSE at baseline. There was no difference in baseline frequency between carriers and noncarriers  and exercise . Reducing/stopping smoking was reported by 8% female carriers vs 1% NC (P=0.04) and 4% male carriers vs 13% NC. Female carriers were more likely than female noncarriers to report taking vitamins (P=0.02). There were no differences between male carriers and noncarriers.Altogether, 52% of female carriers (43% noncarriers) and 44% of male carriers (44% noncarriers) reported having done something else to help them stay healthy and/or avoid cancer. They reported changes in diet , eight  gene carriers had difficulties obtaining health insurance  and two women had their premiums increased (not known which insurance)). Thus, in total, 13 female carriers (20%) experienced some form of insurance problem during the year following genetic test. In addition, one woman who was a noncarrier had difficulties with life insurance, where the company involved refused to remove a loaded policy premium. We do not have further details regarding why these individuals experienced problems with their insurance.This study is unique in clarifying what happens during the year following BRCA1/2 genetic testing now it is becoming routine clinical practice. Our sample includes a substantial group of men, most of whom are over 50 years and have children. Male participants did not report poorer general mental health scores following genetic testing. For female gene carriers, worry and mental health problems were highest during the month following receipt of the genetic test result. These adverse reactions gradually returned to pre-test baseline levels over the following 12 months. For noncarriers, there was an immediate and sustained lowering of cancer-related worry from baseline levels. In this respect, noncarriers derived most benefit to their mental health, whereas carriers, after an initial increase, continued to experience the same level of worry as pre-testing. This reflects the findings from other studies  reported a reduction in their risk of developing cancer.Given that one aim of predictive testing for BRCA1/2 is to reduce mortality by regular surveillance or surgery, it is important to clarify concerns and support those having difficulty engaging in appropriate risk management options. In terms of risk management, this study provides some useful data on the cohort of carriers and noncarriers, which has not been reported elsewhere. Carriers were likely to engage in risk management, noncarriers were less likely to engage in risk management, as expected. However, although noncarriers do not have a BRCA1/2 mutation that predisposes them to breast/ovarian cancer at a younger than expected age, they are still at population risk. Sporadic breast/ovarian cancers are most likely to occur after the menopause; therefore, it is possibly of concern that a significant proportion of noncarriers report reducing the frequency of BrSE following their test result, and this is generally in older women. It is not clear, however, if this merely represents a drop in BrSE to that of the general female population. Nonetheless, this may be a potential area for additional information to noncarriers as they remain at population risk for breast cancer and this risk increases with age. In all, 41% of female noncarriers over 50 years had received a mammogram in the year following testing. This would appear in keeping with the 3-yearly interval of the UK national breast-screening programme. Nevertheless, it is important to ensure that women do not interpret a negative genetic testing as eliminating their cancer risk. It may be that 12 months is too short a time period to fully assess the overall impact of testing on participation in screening programmes or uptake of risk-reducing surgery. A further assessment at 3 years following testing is currently ongoing and these data will be reported in due course.It is striking that a number of women had risk-reducing surgery  prior to genetic testing. The majority of these were subsequently identified as noncarriers. Most will have had this surgery prior to the availability of genetic testing. For the two noncarriers who had BRMx and the 19 who had BROx, this surgery might have been avoided if genetic testing had been available to them when surgery was being contemplated. In this respect, genetic testing will likely save some women unnecessary surgery and reduce costs to the NHS and the women themselves. On this basis, risk-reducing surgery should preferably not be offered to unaffected women until the possibility of having a genetic test to clarify her status has been fully explored.There was no evidence to suggest that having risk-reducing surgery reduced the levels of cancer worry, or avoidant/intrusive thoughts 1 year following testing. This merits further investigation as worry levels in gene carriers remained high over the year following genetic testing. It may be the case that some women had only just completed their surgery on either their breasts or ovaries (BRMx or BROx), and had not yet had intended surgery on the other organ still at risk. It would be helpful to ascertain why there was a residual high level of cancer-related worry where women had risk-reducing surgery, as these data would appear to contradict other available evidence (Three noncarriers chose to remain in the IBIS (Tamoxifen) chemoprevention trial in the year following genetic testing, and could have been discharged from this study on the basis that they no longer met criteria for inclusion.Few individuals regretted their decision to have a predictive genetic test and most were pleased. However, 20% of female gene carriers experienced some form of insurance discrimination during the year following genetic testing, which is high, considering that some will not have applied for insurance in the year following testing. We do not have more detailed information on insurance-related problems at this stage, but we are collecting additional information at 3-year follow-up. Even one case of discrimination gives rise to worries about the use of genetic information by the insurance industry. Given that there is currently a moratorium on using genetic testing results in calculating insurance premiums , it is oStudy participants were recruited from nine centres offering genetic testing for BRCA1/2 between 1996 and 2000. Three centres recruited most participants as they had an established clinical service in place at the time the study began. Far fewer individuals were recruited from other centres; therefore there may be some differences in participant responses that are a factor of the clinical service. However, these data provide an important overview of patient experiences in the period following testing in a group of centres, providing a significant proportion of genetic testing during the recruitment period. Nonresponders at follow-up did not have significantly different worry, mental health or risk perception scores at baseline, and did not differ significantly in terms of demographic characteristics. We do not know the carrier status of nonresponders.In summary, these data illustrate that while general mental health and cancer-related worry are reduced in noncarriers in the year following testing, carriers receive few psychological benefits from discovering their carrier status – particularly among younger women. In the future, genetic testing is likely to become more accessible and more rapid. Pre-test counselling should continue to be provided. Younger women appear to be the most vulnerable group. Many carriers in this cohort, especially younger women, experienced increased levels of distress in the short term following disclosure of their test result, which then returned to pre-test levels. In addition to the absence of psychological benefits of testing in younger female carriers, there is no clear evidence regarding the medical or psychological benefits of continued breast/ovarian surveillance in this group; however, this requires further investigation. It is important that genetic counselling and support is also available in clinics following disclosure of the test result in order to address concerns, receive information to make informed choices and continue to be supported both medically and psychologically. The development of carrier clinics may improve access to information and support. Regular updates of new options via leaflets, information packs, the Internet or family study days will keep patients up to date. Mental health liaison services should also be made available for those experiencing persistent distress.


Sir,A large number of studies have been published investigating the occurrence of second primary cancers following the diagnosis of an ‘index’ cancer. The standard method of analysis is to compare the observed numbers of subsequent cancers with the numbers expected on the basis of cancer incidence rates in the general population . To do this, the number of ‘person-years at risk’ is calculated, with the ‘at risk’ period for each individual starting at the date of diagnosis of the index cancer and terminating at the study cutoff date, the date of death or loss to follow-up, or the date of diagnosis of the subsequent cancer of interest. If the treatment for the index cancer entails removal of the organ in which this occurred, then it seems sensible when investigating the occurrence of second cancers at the same anatomical site to terminate the ‘at-risk’ period at the point when the removal occurred, as a subsequent primary cancer cannot arise in an organ that no longer exists.For example, a woman with breast cancer who undergoes a total mastectomy is no longer at risk for subsequent ipsilateral breast cancer, but she does remain at risk for subsequent contralateral breast cancer. Consequently, ipsilateral and contralateral cancers should be treated differently in the calculation of time at risk. For contralateral breast cancer, the standard method of calculating time at risk applies. However, for ipsilateral breast cancer the ‘at-risk’ period should be truncated at the date of mastectomy if this has been performed. Expected numbers of subsequent ipsilateral and contralateral breast cancers are then calculated by multiplying the ‘at-risk’ period by half the standard breast cancer incidence rate, and the two added together to give the total expected number of subsequent breast cancers.in situ (in situ disease had been detected.Failure to correct for mastectomies leads to underestimation of the standardised incidence ratios (SIRs) for ipsilateral tumours. This is because, without the correction, mastectomy cases are considered to be at risk until the cutoff date at the end of the study. As a result, person-years at risk (and hence estimated expected numbers) are inflated. An example of this effect is given in in situ separately for ipsilateral and contralateral tumours, but it is not clear whether they allowed for mastectomies. Moreover, they applied the overall incidence rates from the general population to each group , thus leading to expected numbers which were twice, and SIRs which were half, the true values. This issue of applying half-rates was addressed by This problem has been recognised for some time. Similar arguments would apply in other situations involving organ removal – for example, hysterectomies should be taken into account when looking at subsequent occurrences of cervical or uterine cancers. These issues should be borne in mind when investigating the occurrence of second cancers.


In a population-based cohort study of all women aged over 50 years with breast cancer in the Swedish Cancer Register in 1961–2003, those diagnosed before 31 December 1987 were regarded as unexposed to tamoxifen, whereas those diagnosed after that date were considered potentially exposed. Crosslinkages within the Cancer Register and the Registers of Death and Emigration enabled follow-up. Standardised incidence ratios (SIRs) of oesophageal and gastric cancer represented relative risks. Among 138 885 cohort members contributing with 1 075 724 person-years of follow-up, we found a nonsignificantly increased risk of oesophageal adenocarcinoma during the potential tamoxifen exposure period  0.83–3.08), but the risk estimates decreased with increasing latency interval. No association was observed during the unexposed period. No increased risk of cardia adenocarcinoma was identified in either period. The risk of non-cardia gastric adenocarcinoma was increased in the potential tamoxifen period , and almost doubled  in the period of longest latency (10–14 years). The corresponding overall SIR was increased in the unexposed group also, but here SIR did not increase with longer latency intervals. An increased risk of tobacco-related tumours, that is, oesophageal squamous-cell carcinoma and lung cancer, was limited to the unexposed cohort, indicating that confounding by smoking might explain the increased SIR during the unexposed period. We concluded that there might be a link between tamoxifen and risk of non-cardia gastric adenocarcinoma. The male predominance is a striking but as yet unexplained characteristic shared by patients diagnosed with oesophageal and gastric adenocarcinoma. The male to female ratio for oesophageal and cardia adenocarcinoma is about 6–7 to 1, whereas this ratio is about 2–3 to 1 for non-cardia gastric adenocarcinoma . As thisWhereas the limited available literature does not support a role of oestrogen in the aetiology of oesophageal adenocarcinoma , that is, the ratio of observed to expected number of newly diagnosed oesophageal and gastric cancer cases. The expected number of cases was calculated by multiplying the observed number of person-years by age-specific and calendar year-specific incidence rates, in 5-year interval, derived from the entire Swedish female population. When calculating the 95% confidence interval (CI) of SIR, we assumed that the number of cases followed a Poisson distribution. All oesophageal and gastric cancer diagnoses occurring within 1 year of follow-up after the primary breast cancer diagnosis were excluded to minimise surveillance bias, that is, a patient with a newly diagnosed breast cancer would be more likely to have another cancer diagnosis detected because of the ongoing diagnostic investigations for the breast cancer. As widespread use of tamoxifen in Sweden only began in the late 1980s , we identified 19 patients with oesophageal adenocarcinoma  . In the n=24), that is, without specification of histologic type, yielded results similar to the analysis of the specified adenocarcinoma cases (data not shown).Among 119 148 breast cancer patients, contributing 892 555 person-years of follow-up, for whom data on the cardia site were available (from 1970), we identified 21 cases of gastric cardia adenocarcinoma . The risn=598), gastric adenocarcinoma without site-specific information (n=503), and gastric non-cardia cancer without histologic specification (n=405), the risk estimates were all generally similar to those presented for tumours specified as gastric non-cardia adenocarcinomas (data not shown).During follow-up of the cohort of 119 148 patients with 892 555 person-years (from 1970), 341 cases of gastric non-cardia adenocarcinoma were identified, which meant an overall increase in the risk of this cancer  . In the In the cohort unexposed to tamoxifen, there was an overall increase in the risk of oesophageal squamous-cell carcinoma  and also seemingly in the risk of lung cancer . In the potentially exposed cohort, no such increase in the risk of either oesophageal squamous-cell carcinoma  or lung cancer  was found.In this study, we found no significant increase in the risk of oesophageal adenocarcinoma among women with breast cancer, and no link between breast cancer and gastric cardia adenocarcinoma. An overall increase in the risk of gastric non-cardia adenocarcinoma was found, and although the risk estimate of gastric non-cardia adenocarcinoma was higher in women not exposed to tamoxifen than in potentially tamoxifen-treated women, an influence of tamoxifen may conceivably still exist. The increased risk of both oesophageal squamous-cell carcinoma and lung cancer during the unexposed period indicates an increased level of smoking among women with breast cancer during this period. No such increases were found during the potential exposure to tamoxifen period. As smoking is linked with a two- to three-fold increase in the risk of gastric non-cardia adenocarcinoma (This is the largest study to investigate oesophageal or gastric adenocarcinoma risk after breast cancer. We used a population-based cohort design and included virtually all postmenopausal female breast cancer patients throughout Sweden diagnosed during a period of more than 40 years. This should have reduced the risk of selection bias and chance errors. Furthermore, the Cancer Register data are of high validity (H. pylori, but potential confounding any of these factors does not seem likely to explain the pattern of elevated risks identified in this study. Gastrooesophageal reflux and infection with Helicobacter pylori have not been associated with breast cancer, thus eliminating these as confounders. Lastly, despite the large number of person-years followed up in this study, the low incidence of oesophageal and cardia adenocarcinoma among women implied imprecise risk estimates, and although we did not identify an association between tamoxifen and oesophageal adenocarcinoma with statistical significance, the point estimates showed that in view of the risk of a type II error, a true association cannot be ruled out. The results regarding gastric cancer were, however, more robust.Furthermore, confounding might have influenced our result. The increased SIR for gastric cancer in our breast cancer cohort indicates that this cohort is exposed to additional risk factors for gastric cancer compared to the background female population. Our analysis of SIR inherently adjusts for confounding by age and calendar year, and as discussed above, we assessed influence of tobacco smoking through analysis of tobacco-related cancer. Confounding by smoking might be of particular relevance for the interpretation of our results. Knowledge of the hazard of smoking may have had a larger impact on the smoking habits of breast cancer patients compared to the background population and more so during the years 1988–2003 than in the earlier period when the risks related to smoking were less known. We could not adjust for other possible confounding factors, that is, socio-economic status, heredity, diet, body mass, reflux disease, and infection with The few previous studies that have addressed sex hormonal influence in the aetiology of oesophageal and cardia adenocarcinoma do not support any such influence, which seems to be in line with our results. No decreased risk of oesophageal adenocarcinoma was observed in a cohort of prostate cancer patients treated with oestrogen , or amonOur study indicates that women with breast cancer are at increased risk of gastric adenocarcinoma, and antioestrogen therapy might explain this finding. Recently, a unique global pattern in the male to female ratio of the incidence of gastric adenocarcinoma was reported, indicating a 10–15-year delay in this cancer among female subjects compared to male subjects, possibly owing to the oestrogen exposure . We haveIn conclusion, this study indicates that women who have had a breast cancer diagnosis are at an increased risk of later developing non-cardia gastric adenocarcinoma, possibly as a result of tamoxifen exposure. No such effect was clearly demonstrated for oesophageal or cardia adenocarcinoma. This study should encourage further studies of the influence of sex hormonal influence in the aetiology of these tumours.


The relationship between lifestyle factors, past medical conditions, daily meal frequency, diet and the risk of 'familial' colorectal cancer has been analysed using data from a case-control study conducted in northern Italy. A total of 1584 colorectal cancer patients and 2879 control subjects were admitted to a network of hospitals in the Greater Milan area and the Pordenone province. The subjects included for analysis were the 112 cases and the 108 control subjects who reported a family history of colorectal cancer in first-degree relatives. Colorectal cancer cases and control subjects with family history were similarly distributed according to sex, age, marital status, years of schooling and social class. Familial colorectal cancer was associated with meal frequency, medical history of diabetes  and cholelithiasis (RR = 5.2). Significant positive trends of increasing risk with more frequent consumption were observed for pasta , pastries (RR = 2.4), red meat (RR = 2.9), canned meat (RR = 1.9), cheese (RR = 3.5) and butter (RR = 1.9). Significant inverse associations and trends in risk were observed for consumption of poultry (RR = 0.4), tomatoes (RR = 0.2), peppers (RR = 0.3) and lettuce (RR = 0.3). Significant inverse trends in risk with increasing consumption for beta-carotene and ascorbic acid were observed . These results suggest that risk factors for subjects with a family history of colorectal cancer in first-degree relatives are not appreciably different from recognized risk factors of the disease in the general population.