Breast cancer is a partially heritable trait and genome-wide association studies (GWAS) have identified over 180 common genetic variants associated with breast cancer. We have previously performed breast cancer GWAS in Latinas and identified a strongly protective single nucleotide polymorphism (SNP) at 6q25, with the protective minor allele originating from indigenous American ancestry. Here we report on fine mapping of the 6q25 locus in an expanded sample of Latinas.We performed GWAS in 2385 cases and 6416 controls who were either US Latinas or Mexican women. We replicated the top SNPs in 2412 cases and 1620 controls of US Latina, Mexican, and Colombian women. In addition, we validated the top novel variants in studies of African, Asian and European ancestry. In each dataset we used logistic regression models to test the association between SNPs and breast cancer risk and corrected for genetic ancestry using either principal components or genetic ancestry inferred from ancestry informative markers using a model-based approach.p = 3.3 × 10− 8 - 6.0 × 10− 9) not in linkage disequilibrium (LD) with variants previously reported at this locus. These SNPs were in high LD (r2 > 0.9) with each other, with the top SNP, rs3778609, associated with breast cancer with an odds ratio (OR) and 95% confidence interval (95% CI) of 0.76 (0.70–0.84). In a replication in women of Latin American origin, we also observed a consistent effect . We also performed a meta-analysis of these SNPs in East Asians, African ancestry and European ancestry populations and also observed a consistent effect .We identified a novel set of SNPs at the 6q25 locus associated with genome-wide levels of significance  contains supplementary material, which is available to authorized users. BRCA1 [BRCA2 [Breast cancer is a partially heritable disease. Mutations in several high-penetrance genes including BRCA1 , BRCA2 [1 [BRCA2 , and oth1 [BRCA2  are asso1 [BRCA2 –20. The 1 [BRCA2  and in L1 [BRCA2 , 23.ESR1 and CDCC170 in an East Asian population [Several GWAS studies have identified SNPs at 6q25 that are associated with breast cancer risk , 23–27 apulation . The locpulation , 31. MorHispanic/Latino populations are the second largest ethnic group in the USA  and yet San Francisco Bay Area breast cancer study (SFBCS): the SFBCS is a population-based multiethnic case–control study of breast cancer. Patients (cases) aged 35–79 years diagnosed with invasive breast cancer from 1995 to 2002 were identified through the Greater Bay Area Cancer Registry. Controls were identified by random-digit dialing and matched on 5-year age groups. Blood collection was initiated in 1999. For this study, we focused only on patients and matched controls who self-identified as Latina or Hispanic and included 351 cases and 579 controls. Samples from this study were used as part of the initial discovery set.Breast Cancer Family Registry (BCFR): the BCFR is an international, National Cancer Institute (NCI)-funded family study that has recruited and followed over 13,000 breast cancer families and individuals with breast cancer with strong likelihood of genetic contribution to disease. The present study includes samples from the population-based Northern California site of the BCFR. Cases in patients aged 18–64 years diagnosed from 1995 to 2007 were ascertained through the Greater Bay Area Cancer Registry. Cases in patients with indicators of increased genetic susceptibility  were oversampled. Cases not meeting these criteria were randomly sampled.Population controls were identified through random-digit dialing and frequency-matched on 5-year age groups to cases diagnosed from 1995 to 1998. We included 641 cases and 61 controls who self-identified as Latina or Hispanic from this study. Samples from this study were used as part of the initial discovery set.Since the SFBCS and BCFR were recruited from the same region and during an overlapping time frame, we combined these datasets to search for relatives. After removing relatives  and samples that overlapped with the Kaiser Research Project on Genes, Environment and Health, we included 942 cases and 589 controls from these studies.Multiethnic cohort (MEC): the MEC is a large prospective cohort study in California (mainly Los Angeles County) and Hawaii. The breast cancer study is a nested case–control study including women with invasive breast cancer diagnosed at the age of > 45 years and controls matched on age (within 5 years) and self-identified ethnicity. After removing relatives , we used phenotypic and genetic data from 520 Latina breast cancer cases and 1544 matched Latina controls. Samples from this study were used as part of the initial discovery set.N = 3801). We included both incident and prevalent cases  in our analyses. We identified 44 women who were also included in the SFBCS. The genetic data from these participants were included as part of the RPGEH since we considered the Affymetrix Lat array as a more comprehensive array than the Affymetrix 6.0 array. After removing relatives, we included a total of 225 cases and 3574 controls. Samples from this study were used as part of the initial discovery set.Research project on genes environment and health (RPGEH): the RPGEH is a large cohort study of over 100,000 men and women of all racial/ethnic groups who are members of the Kaiser Permanente Health Plan. This analysis focuses only on women who are of self-reported Latina/Hispanic ethnicity (Cancer de mama (CAMA) study: this study is a population-based case–control study of breast cancer conducted in Mexico City, Monterrey, and Veracruz. Patients (cases) aged 35–69 years diagnosed between 2005 and 2007 were recruited from 11 hospitals (3–5 in each region). Controls were recruited based on membership in the same health plan as the cases and are frequency-matched on 5-year age groups. For the current study, we used phenotypic data and DNA samples from 1008 women with breast cancer and 1063 controls. Of these, 698 cases and 599 controls were genotyped with the Illumina Oncoarray and included in the discovery. An additional 310 cases and 464 controls were included as part of the replication dataset.Colombian Study of Environmental and Heritable Causes of Breast Cancer (COLUMBUS): COLUMBUS is a population-based case–control study of breast cancer conducted in four cities: Bogota, Ibague and Neiva from the Central Colombian Andes region, and Pasto, from the Colombian South. Patients aged 18–75 years, with incident cases of invasive breast cancer, have been recruited in two population registries and two large cancer hospitals. Recruitment started in 2011. Cancer-free controls were recruited through the same institutions and were matched on education, socioeconomic status and local origin using a genealogical interview. In the current study, we used data from 954 cases and 769 controls for the replication study.BRCA1/2 testing after providing informed consent. In the current study we genotyped 1148 cases. The 347 unaffected female Latina controls were from Southern California and were invited to participate at community health fairs, via flyers, and at City of Hope. These samples were used as part of the replication study.Hereditary Cancer Registry of City of Hope (HCRCOH) : Latina breast cancer cases are part of the HCRCOH through the Clinical Cancer Genetics Community Research Network (CCGCRN). The CCGCRN includes cancer center and community-based clinics that provide genetic counseling to individuals with a personal or family history of cancer . All patAfrican American breast cancer GWAS (AABC): the GWAS includes African American participants from nine epidemiological studies of breast cancer, comprising a total of 3153 cases and 2831 controls  study, 380/224; the Women’s circle of health study (WCHS), 272/240; the SFBCS, 172/231; the Northern California Breast Cancer Family Registry (NC-BCFR), 440/53;the Carolina breast cancer study (CBCS), 656/608; The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) Cohort, 64/133; the Nashville breast health study (NBHS), 310/186; and the Wake Forest University breast cancer study (WFBC), 125/153). Additional details have previously been reported , 39. TheThe ROOT consortium included six studies and a total of 1657 cases and 2029 controls of African ancestry: the Nigerian Breast Cancer Study (NBCS), 711/624; the Barbados national cancer study (BNCS), 92/229; the Racial variability in genotypic determinants of breast cancer risk study (RVGBC), 145/257; the Baltimore Breast cancer study (BBCS), 95/102; the Chicago cancer prone study (CCPS), 394/387; and the Southern community cohort (SCCS), 220/430. Additional details can be found elsewhere . These sShanghai breast cancer genetics study: study participants were drawn from four population-based studies conducted in Shanghai, the Shanghai Breast Cancer Study (SBCS), Shanghai Women’s Health Study (SWHS), Shanghai Breast Cancer Survival Study (SBCSS), and the Shanghai Endometrial Cancer Study (SECS (which contributed control data only). The SBCS is a population-based, case-control study conducted in urban Shanghai. Subject recruitment in the initial phase of the SBCS (SBCS-I) was conducted between August 1996 and March 1998. The second phase (SBCS-II) of recruitment occurred between April 2002 and February 2005. Breast cancer cases were identified through the population-based Shanghai Cancer Registry and supplemented by a rapid case-ascertainment system. Controls were randomly selected using the Shanghai Resident Registry. The SBCSS included newly diagnosed breast cancer cases ascertained via the Shanghai Cancer Registry between April 2002 and December 2006. The SECS is a population-based, case–control study of endometrial cancer conducted between January 1997 and December 2003 using a protocol similar to the SBCS; only community controls from the SECS were included in the present study. The SWHS is a population-based prospective cohort study of women recruited between 1996 and 2000. The cohort has been followed by a combination of record linkage and active follow up to identify cause-specific mortality and cancer incidence by sites. All these studies are conducted among Chinese women in Shanghai, using very similar protocols in data and sample collection. There were 2731 cases and 2135 controls genotyped with an Affymetrix 6.0 array and 1794 cases and 2059 controls genotyped with an Illumina MEGA array. These subsets were analyzed separately and included in a meta-analysis as part of the replication study.http://bcac.ccge.medschl.cam.ac.uk/bcacdata/oncoarray/) and used the summary statistics from the combined analysis of individuals of European ancestry from the Oncoarray and iCOGS consortia.European ancestry GWAS data: we also evaluated the top SNPs using summary statistics from a recent large GWAS of European-ancestry breast cancer cases and controls . We downThe SFBCS and NC-BCFR samples were all genotyped with an Affymetrix 6.0 arrays at the University of California, San Francisco (UCSF). The MEC samples were genotyped with an Illumina 660 array at USC (520 Latina women with breast cancer and 546 matched Latina controls) and an additional 998 controls were typed on an Illumina 2.5 M array at the Broad Institute . The RPGEH samples were typed on an Affymetrix LAT array at UCSF. The CAMA samples were typed on an Ilumina Oncoarray at the Quebec Genome Center. The COLUMBUS samples were typed on an Affymetrix Biobank Array. Genotyping in the AABC consortium was conducted using the IlluminaHuman1M-Duo BeadChip. Genotyping in the ROOT consortium was conducted using the Illumina HumanOmni2.5-8v1 array at Johns Hopkins University Center for Inherited Disease Research. A subset of the Shanghai Breast Cancer Genetics Study (SBCGS) samples were typed on an Affymetrix 6.0 array. After quality control exclusions, the final data set included 2731 cases and 2135 controls. A second subset of the SBCGS were genotyped on an Illumina MEGA array. After quality control exclusions, the final data set included 1794 cases and 2059 controls. Data for four SNPs identified in the discovery stage were extracted from the SBCGS datasets and were included in the replication stage.The CAMA samples and the CCGCRN samples, were genotyped using Taqman probes for rs3778609. The CAMA samples that were not included in the GWAS were genotyped at 106 ancestry informative markers from genotyped on a Sequenome platform as previously described . CCGCRN N = 192,795) and imputed from those since we found that if imputing them separately and then analyzing them together produced a large number of false positives. Each of the remaining GWAS datasets were submitted to the HRC server individually for imputation. Only variants with imputation quality scores of R2 > 0.5 were selected for additional analysis. In a separate analysis, we imputed each of the datasets to the 1000 Genomes Reference Version 3 (October 2015 release) [Samples with > 5% missing genotypes were removed from each dataset. We dropped variants with > 5% missing data from each dataset. Since excess homozygosity is more common in populations with substructure, particularly with ancestry informative markers, we did not use deviation from Hardy-Weinberg equilibrium as a criterion for excluding markers. All datasets were entered mapped to Hg19. Each dataset was then phased using SHAPEIT and imputed using the Haplotype Reference Consortium (HRC) with Minimac3 . For therelease)  with MinIMPUTE2 software [IMPUTE2 software [Genotype imputation for the ROOT consortium was conducted using the software  with thesoftware . Genotypsoftware  to a cosThe Shanghai Breast Cancer Study GWAS data were phased with Minimac2 and imputed with SHAPEIT using 1000 Genomes Project phase 3. Only SNPs with a minor allele frequency (MAF) ≥ 0.01 and high imputation quality (RSQR ≥ 0.5) were included in the analyses.We used KING  to identWe genotyped rs3778609, the top novel SNP, in the CAMA study in samples that also had GWAS data and checked the concordance between genotyped and imputed results.r2 > 0.2 in PLINK. With the remaining data, we determined the PCs using EIGENSTRAT [We implemented principal component (PC) analysis to assess genetic ancestry in each of the discovery datasets in unrelated individuals. To do so, we first LD-pruned typed SNPs with GENSTRAT  within sGENSTRAT  to calcuR2 in the controls in our dataset using PLINK. We then performed conditional analyses by entering the most significant SNP in the model as a covariate in addition to PCs 1–10. We evaluated genome-wide inflation by estimating λ (λ ≤ 1.0 indicates no inflation). To test for heterogeneity with family history and study site we entered these as multiplicative interaction variables with the SNPs of interest in the logistic regression models and tested the significance of the interaction variables. To test for heterogeneity by age, we dichotomized at age 50 years and also tested for a multiplicative interaction with the SNPs. In addition, we re-tested the associations for the top SNPs adjusting for genetic ancestry from ADMIXTURE using logistic regression models. Heterogeneity analyses and the analysis of the top SNPs using ancestry estimates from ADMIXTURE were performed using Stata (Version 14).We performed single-variant association testing using logistic regression models and adjusting for PCs 1–10 in PLINK . For theBased on the sample size for discovery (2385 cases and 6416 controls) we had ~ 80% power to detect an odds ratio of 1.25, 1.365, and 1.49 with allele frequencies of 0.4, 0.2, and 0.1 respectively.R2 > 0.5) and that have a p value that is at within 2 log (base 10) level of significance compared to the top SNP. We then entered each index SNP with the other SNPs from that cluster into regulomeDB [For each of the top index SNPs  we identified all of the other SNPs that they are in LD with  and another six were in moderate (0.39 < r2 < 0.49) LD with rs140068132, and none of these were significant in joint models with rs140068132  with each other and in low LD (r2 < 0.2) with rs140068132. These SNPs include rs851984, which has been previously reported to be associated with breast cancer [r2 > 0.9) with each and in low LD (r2 < 0.2) with rs140068132 or rs851985 and with other SNPs previously reported at this locus  between them, we found three distinct clusters of SNPs (haplotypes) associated at a genome-significant level  of the genotypes being in concordance.N = 2412; N = 1620; OR = 0.88; 95% CI 0.78–0.99; p = 0.037, Table We used data from the portion of the CAMA study that did not have GWAS data, the COLUMBUS study and the CCGCRN to replicate the association with rs3778609. We found a consistent direction in all three studies and a nominally significant association in a meta-analysis of the three studies  lower odds ratio for ER-negative than for ER-positive breast cancer. We also found a significantly stronger (p = 0.025) effect size for ER-negative breast cancer for rs3778609. The effect size for rs851980 is also greater for ER-negative breast cancer; however, the difference between ER-negative and ER-positive breast cancer for this SNP was not statistically significant (p = 0.068).We analyzed the association for each of the top SNPs separately and jointly by ER-status Table . As we hp = 0.13), age (p = 0.71), or family history (p = 0.61).We also evaluated for other sources of heterogeneity for rs3778609 including location (San Francisco Bay Area versus Los Angeles versus Mexico), age (dichotomizing at age 50 years) and family history. We found no evidence of heterogeneity with study site  for imputation, which includes a large number of reference individuals; however, the proportion of individuals with indigenous American ancestry in the HRC is low, and therefore, we are likely underpowered to detect rare variants that originate from American ancestry. The common variants that we report here are in the range that imputation from HRC is known to be relatively high quality. Furthermore, we validated our imputed results in one of the datasets by genotyping and found excellent correlation. Thus, we believe the new SNPs we report are based on relatively accurate imputation. However, we are likely missing some variants, particularly low-frequency variants from indigenous American origin. As imputation panels improve, we will be able to impute lower-frequency variants with more accuracy and may be able to detect new associations.The effect size we observed in the replication dataset is substantially lower than in the discovery dataset, likely due to regression towards the mean, a well-known phenomenon in GWAS, since the top SNPs in a discovery dataset are likely to have some upward bias in the effect size . HoweverOur study demonstrates additional unique associations with variants at 6q25 and breast cancer risk. This further highlights the important contribution of this locus to breast cancer susceptibility, particularly ER-negative breast cancer susceptibility. Additional fine-mapping and functional studies are needed to elucidate all of the causal variants in our population. However, the variants we identified in this study can be useful to add to the increasing pool of common variants coming from GWAS and will be particularly useful to risk-stratify women of Latin American ancestry for breast cancer risk.Additional file 1:Table S1. Association statistics and imputation accuracy for all SNPs with p value <5 × 10–7 in discovery dataset. Also included are results for models that are conditional on top SNPs and the and linkage disequilibrium between index SNPs described in the manuscript and other SNPs in this list. (XLSX 29 kb)Additional file 2:Tables S2-S5. Supplementary tables including linkage disequilibrium between top SNPs and previously described SNPs at this locus. Association results for top SNPs with imputation to 1000 Genomes. Association results for top SNPs adjusted for ancestry using ADMIXTURE results. Association results for SNPs previously reported as genome wide significant at 6q25. (DOCX 27 kb)Additional file 3:Table S6. Results of the top candidate SNPs analyzed using RegulomeDB (XLSX 12 kb)


Fibroadenomas are common benign breast lesions, and studies of European American women indicate a persistent, increased risk of breast cancer after diagnosing a fibroadenoma on biopsy. This association has not been independently assessed in African American women, despite reports that these women are more likely to present with fibroadenomas.The study cohort included 3853 African American women with a breast biopsy completed between 1997 and 2010 in metropolitan Detroit. Biopsies were microscopically reviewed for benign breast lesions, including fibroadenoma, proliferative disease, and atypia. Risk of breast cancer within the cohort was estimated using relative risk ratios and 95% CIs calculated using multivariable log-binomial regression. Relative risk of breast cancer in this cohort compared with African American women in the broader metropolitan Detroit population was estimated using standardized incidence ratios (SIRs).p = 0.008 for lobular hyperplasia; all other p values < 0.01). Unlike women with other benign lesions , women with fibroadenomas did not have an increased risk of developing breast cancer compared with the general population . Biopsies that indicated a fibroadenoma were associated with a reduced risk of breast cancer after adjusting for age at biopsy, proliferation, and atypia  compared with biopsies without a fibroadenoma.Fibroadenomas occurred more frequently in biopsies of younger women, and other types of benign breast lesions were less likely to occur when a fibroadenoma was present  contains supplementary material, which is available to authorized users. Over 1.5 million breast biopsies are pathologically assessed annually in the United States, indicated by abnormal mammography findings or patient complaints –4. TheseOne type of BBD, fibroadenomas, are well-circumscribed benign tumors of epithelial and stromal tissue Fig.  6]. Bre. Bre6]. African American women have a 42% higher breast cancer mortality rate than European American women , a burdeAfrican American women with their first benign breast biopsies conducted between 1997 and 2010 were identified using University Pathology Group  records. UPG provides pathology services to several hospitals in metropolitan Detroit. Women aged 18 to 84 years at the time of benign breast biopsy were eligible for this institutional review board-approved study. Exclusionary criteria included a diagnosis of invasive or in situ breast carcinoma before or within 6 months of the breast biopsy, a history of mastectomy or reduction mammoplasty, lipoma, fat necrosis, epidermal cysts, hematoma, accessory structure, phyllodes tumor, or a lymph node biopsy without breast tissue. For this type of study, the Wayne State University Institutional Review Board determined that formal consent was not required.n = 23).Core needle and excisional benign biopsies were microscopically reviewed by blinded study pathologists  using original H&E-stained slides. Slides from the first biopsy were assessed for the presence of 12 pathologic lesions, including apocrine metaplasia, calcifications, columnar alterations, cysts, duct ectasia, ductal hyperplasia, fibroadenoma, fibrosis, intraductal papilloma, lobular hyperplasia, radial scars, and sclerosing adenosis. The biopsies were additionally categorized into three groups using criteria described by Dupont and Page [Women who developed breast cancer were identified through hospital medical records and also through the use of the Metropolitan Detroit Cancer Surveillance System (MDCSS), a founding member of the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program. MDCSS collects cancer incidence, treatment, and survival data in the tricounty metropolitan Detroit area. Use of both data sources allowed the identification of cancers in women residing in the entire tricounty metropolitan Detroit area. Women were matched between UPG records and MDCSS using name, date of birth, and/or Social Security number; follow-up information was complete to December 31, 2015. Median length of follow-up was 13.3 years ; median time to breast cancer diagnosis was 6.6 years .Associations between fibroadenoma and other benign lesions were examined using chi-squared tests. Relative risks of breast cancer associated with biopsies, with or without fibroadenoma, were estimated using age-adjusted standardized incidence ratios (SIRs) calculated from SEER estimates of cancer incidence in African American women in MDCSS from 1999 to 2014. Risk of breast cancer associated with fibroadenomas relative to other nonfibroadenoma BBD was examined within the cohort by relative risk ratios and 95% CIs calculated using multivariable log-binomial regression and adjusting for age at biopsy. Regression models were further adjusted using backwards selection based on Bayesian information criteria. Models were stratified by age (below or above 50 years) to estimate risk based on likely menopausal status. Time to breast cancer diagnosis was assessed using competing risk analysis with death considered as a competing risk.p < 0.001)   of which were diagnosed with fibroadenoma. Fibroadenomas showed high concordance between pathologists . Women with a fibroadenoma on biopsy were more likely to be under the age of 40 years at biopsy (31.9%) than women without a fibroadenoma on biopsy (18.9%)  of breast cancer compared with the general African American population in metropolitan Detroit  compared with the absence of fibroadenoma within the BBD cohort Table . When thp < 0.001 by Fine and Gray test). Stratifying by likely menopausal status by age indicated the incidence of breast cancers was lower in women under the age of 50 years than in women aged 50 years or older (data not shown). In both strata, women with fibroadenoma on biopsy accumulated fewer cancers over the study period than women without fibroadenoma on biopsy .Women with fibroadenoma on biopsy accumulated fewer breast cancers over the study period than women without fibroadenoma on biopsy Fig.   , 18. BecCurrently, a diagnosis of fibroadenoma requires no further intervention and is followed by a primary care physician or gynecologist unless the patient elects to have a mass removed, usually due to size of the tumor, recurrence, or pain , 24. BecAdditional file 1:Table S1. Distribution of benign breast features and other characteristics by fibroadenoma status in women under the age of 50 years. Table S2. Distribution of benign breast features and other characteristics by fibroadenoma status for women aged 50 years or older. (DOCX 32 kb)


BRCA genes account for a small proportion of the familial risk of breast cancer. Low-penetrance alleles are expected to underlie the remaining heritability. By now, there are about 180 genetic polymorphisms that are associated with risk, most of them of modest effect. In combination, they can be used to identify women at the lowest or highest ends of the risk spectrum, which might lead to more efficient cancer prevention strategies. Most of these variants were discovered in populations of European descent. As a result, we might be failing to discover additional polymorphisms that could explain risk in other groups. This review highlights breast cancer genetic epidemiology studies conducted in Latin America, and summarizes the information that they provide, with special attention to similarities and differences with studies in other populations. It includes studies of common variants, as well as moderate- and high-penetrance variants. In addition, it addresses the gaps that need to be bridged in order to better understand breast cancer genetic risk in Latin America.The last 10 years witnessed an acceleration of our understanding of what genetic factors underpin the risk of breast cancer. Rare high- and moderate-penetrance variants such as those in the  Breast cancer is the most common cancer in women, and a major public health concern worldwide . ImproveBRCA1 and BRCA2 genes [ATM, BARD1, PALB2, and CHECK2, explain ~20–25% of breast cancer risk [Only a relatively small proportion of breast cancers can be explained by the presence of high-penetrance genetic mutations, such as those in the A2 genes ,17,18,19cer risk ,22,23 ancer risk ,49,50,51cer risk . HoweverLatin American populations are diverse, not only culturally, but also in their genetic ancestry composition ,53. ThisBRCA), “case–control study” , and “Latinas”  in the PubMed database (https://www.ncbi.nlm.nih.gov/pubmed/). We also added to these terms the name of each Latin American country. We complemented the search by reviewing manuscripts cited in the selected papers. We focused on studies with case series, cohorts, or case/control design, conducted in Latin America and that included genetic factors as main predictors. In some instances, we make reference to studies conducted in or including US Latinas. We only included studies published in the English language. We did not narrow the search by date; the selected studies were published between 2008 and 2018.For paper retrieval, we combined search terms such as “breast cancer” (breast cancer subtypes), “genetics”  in the US; this includes Brazil [BRCA1 to BRCA2 carriers were also observed. While most countries report higher frequencies of BRCA1 mutations, in Costa Rica, Cuba, Puerto Rico, and Uruguay, BRCA2 mutations are predominant [The Hereditary Breast and Ovarian Cancer (HBOC) syndrome is caused by loss-of-function mutations in the  cancers . Despite cancers ,58,59,60s Brazil , Colombis Brazil , Cuba [6s Brazil , Mexico s Brazil ,65, Perus Brazil , and Pues Brazil , for whidominant . This isdominant ,69.BRCA1/BRCA2 carriers in the Ashkenazi Jewish population [BRCA1 185delAG  is the most common pathogenic variant with the largest geographical span as it was shown to be recurrent in Argentina, Brazil, Mexico, and Peru [BRCA pathogenic variants reported in the literature were observed in more than one country of Latin America and the Caribbean [BRCA mutation spectrum and to provide adequate recommendations and treatment in women from Latin America. A previous review by Dutil et al. provided additional information regarding specific BRCA mutations in Latin American women [BRCA genes, there are other high-penetrance mutations that are uncommon in the population , which are associated with well-known familial syndromes [TP53 gene, best known as R337H, was found in 2–7% of Brazilian breast cancer patients [Three founder mutations were shown to account for 79% of the pulation . In Latipulation . The BRCand Peru . In Mexiand Peru . Founderand Peru ,72,74,75aribbean ,77. In aaribbean . In Coloyndromes ,82. For patients ,84,85.Polymorphisms in moderate- and low-penetrance genes may be relatively common in the population, and collectively confer a small to moderate increased relative risk for breast cancer . Common ATM gene in Chile and Mexico [DNA repair is crucial for normal cell function, and common polymorphisms in DNA repair genes or genes that play a role in DNA repair pathways are potential candidates for association with breast cancer risk. Several studies in Latin America assessed the association between DNA repair gene variants and breast cancer risk ,122,123.d Mexico ,100,112.The BARD1 protein heterodimerizes with BRCA1 and induces translocation and retention of BRCA1 into the nucleus . The c.1BRCA1/2 mutations and found two variants, c.1676A>G (rs152451) and c.2993C>T (rs45551636), that were associated with breast cancer risk in a subsequent case–control study [CHEK2 c.1100delC truncating mutation, which increases the risk of breast cancer twofold, was widely analyzed. This mutation has a frequency of 0.3–1.2% in European populations [AKT1 is frequently mutated in mammary tumors [AKT1 and its association with breast cancer risk, as well as histopathological and immunohistochemical characteristics, in 276 Ecuadorian mestizo women. They found that the intronic SNP rs3803304 was associated with breast cancer risk. Moreover, they found that the heterozygous genotype CG of that SNP had a significantly different frequency between intrinsic subtypes (p ≤ 0.05), with luminal B showing the highest frequency (63.6%). This result suggests that the SNP rs3803304 may affect DNA transcription, acting as a risk factor for breast cancer in Ecuadorian mestizo population living in high altitudes.Three other BRCA1 and BRCA2 functionally related genes were screened in Latin American populations. PALB2 binds BRCA2 and recruits it to BRCA1 foci on damaged DNA . Leyton ol study . CHEK2 pol study . The CHEulations  and caseulations ,136,137.y tumors . Activaty tumors . Lopez-Cy tumors  analysedXRCC3 c.722C>T (rs861539) and RAD51D c.698A>G (rs28363284), were assessed for their association with breast cancer risk in high-risk families in Chile without known BRCA1/2 mutations [XRCC3 gene yielded a statistically significant result [XPC and XPD) and ultraviolet (UV) excision repair protein (RAD23B) genes and breast cancer risk [RAD23B and breast cancer risk, and between XPC and RAD23B and DNA repair capacity in the cases [XRCC1 gene and breast cancer risk [TP53, which is an important gene in DNA-repair related pathways [Polymorphisms within two DNA double-strand break repair genes, cer risk . They hyhe cases . Similarcer risk . Variantpathways , were re98A>G rs263284, wepathways ,144,145.pathways ,143,144.pathways . Three o98A>G rs263284, wepathways .TS) gene produces an enzyme that is involved in one-carbon metabolism and is crucial for DNA synthesis. A study in Mexico explored the association between polymorphisms in the TS gene and breast cancer risk and reported negative results [MTHFR) and cystathionine β synthase (CBS) genes, which are involved in the processing of amino acids, and breast cancer risk. Four out of five studies found a positive association [MTHFR messenger RNA (mRNA) expression in triple-negative breast cancer (TNBC) tumors. The 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) gene, also involved in the amino-acid synthesis pathway, was tested in a Brazilian population with no significant results [The thymidylate synthase , androgen (AR), and progesterone receptors (PGR)) yielded mostly negative results except in secondary stratified analyses (by body mass index or use of hormone replacement therapy) [ESR1, PGR, COMT, CYP19A1, and CYP1A1 genes [PGR gene and breast cancer risk [CYP1A1 gene [Sex hormones, their receptors, and other relevant components within their pathways, are thought to be involved in breast cancer development because of their role in cell growth and proliferation. Analyses of a limited number of candidate variants in hormone receptor genes (estrogen (therapy) ,151,152.A1 genes ,150,153.cer risk , while o1A1 gene ,115.MMP-1, MMP-2, MMP-3, and MMP-9 genes and breast cancer risk [MMP-1 , MMP-3 , and MMP-9  genes among women with high Native-American ancestry [MMP-2 c.-1586C>T polymorphism (rs243865) and breast cancer risk [ITGA6) gene and the c.-1562 C>T (rs3918242) polymorphism in the MMP-9 gene, respectively [Matrix metalloproteinases (MMPs) are enzymes that can degrade the extracellular matrix and basement membrane and are thought to play an important role in cell proliferation, migration, differentiation, apoptosis, and angiogenesis . A largecer risk . Signifiancestry . A studycer risk . Other sectively ,158.TNF-α, RETN, CAP1, and PTGS2 genes). No association was detected for nine SNPs evaluated within the PTGS2 gene [TNF-α c.-308G>A (rs1800629) polymorphism was found to be associated with breast cancer risk in a study conducted in Mexico [RETN c.-225C>G (rs1862513) and CAP1 c.881G>A (rs35749351) polymorphisms and breast cancer risk [Different analyses conducted in the Breast Cancer Health Disparities Study samples analyzed tag SNPs in genes related to inflammation and energy balance, taking into account possible interactions with body mass index ,163,164.GS2 gene . The TNFn Mexico , and anocer risk .HER2-overexpressing breast cancer patients [IL-18 gene, c.-838C>A(rs1946518) and c.-368G>T (rs187238), and breast cancer risk [Two studies assessed polymorphisms related to tumor immune response in Brazilian populations, and both of them found statistically significant associations with breast cancer risk ,90. Tumopatients . Banin Hpatients , suggestcer risk ,170. Precer risk ,172.GPX1, GPX2, GPX3, GPX4, SELS, SEP15, SEPN1, SEPP1, SEPW1, TXNRD1, and TXNRD2) and breast cancer risk in US Latinas, finding mostly negative results except when analyses were stratified by genetic ancestry and by tumor subtype [CYP2W1, CYP4F11, CYP8A1, and CYP1B1 [ABCB1, which encodes the MDR1 protein, [GSTM1 and GSTP1, members of the glutathione S-transferase (GST) gene family [eNOS, which can react with other free radicals and damage DNA [CYP genes were mostly negative, except for CYP1B1 [GSTM1 deletion (tagged by rs366631), and ABCB1 c.3435C>T (rs1045642), GSTP1 c.313A>G (rs1695), and eNOS polymorphisms [ABCB1 gene was an important risk factor for breast cancer in premenopausal women and specifically for the TNBC subtype [ABCB1 function, and reduced mRNA and/or protein expression, which might impact the metabolism and posterior elimination of toxic and carcinogenic compounds inducing cellular accumulation leading to cancer development [Selenoproteins were shown to have a redox function and to decrease oxidative stress. One study tested the association between SNPs in different selenoprotein-related genes . These SNPs have a frequency of between 5% and 23% in Latin American populations and are practically absent in all other groups. The minor allele was protective, with an associated odds ratio (OR) of 0.60 : 0.53–0.67) and was more protective for estrogen-receptor-negative (ER−)  than for estrogen-receptor-positive disease  [The first GWAS on Latina women was published in 2014 , reporti49-0.80) .FGFR2, TOX3, and MAP3K1 genes and the 2q35 and 8q24 loci, that were replicated in different populations [FGFR2 (c.109+906T>C (rs2981582), c.109+1899A>G (rs2420946), 109+7033T>A (rs1219648), MAP3K1 (rs889312), TOX3 (rs3803662), 2q35 (rs13387042), and 8q24 (rs13281615) and breast cancer risk in Chilean patients [FGFR2, MAP3K1, TOX3, and 2q35, but not for 8q24 [FGFR2 rs2981582 polymorphism in the Mexican population reported an interaction between the FGFR2 polymorphism and alcohol intake [Some studies conducted in Latin America replicated selected loci that were discovered in breast cancer GWAS conducted in samples of European origin: two in Chile and one in Mexico ,96,116. ulations ,183,184.ulations ,186,187.patients ,96. Theyfor 8q24 ,96. Anotl intake .ESR1 gene mostly observed in women of Indigenous American ancestry.There is a heterogeneous genetic background in Latin American populations, with regional variation in the relative proportions of the three main ancestral continental influences: Indigenous American, European, and African. A study conducted in US Hispanic/Latinas from the Bay Area first reported the association between genetic ancestry and breast cancer risk . Women wA large proportion of the case/control studies described in In this review, we presented a summary of genetic association studies in Latin American women, including studies of relatively rare high-penetrance mutations and those discovered using candidate gene approaches or GWAS, which tend to be of moderate or small effects but are more common.BRCA1- and BRCA2-associated hereditary breast cancers in Latin America emerged. While still incomplete, available evidence points to a unique genetic make-up characterized by remarkable diversity across and within countries [BRCA1 and BRCA2 analysis to extended panels of genes including high- and moderate-penetrance risk genes. Although this approach became standard of care in the US, the data on the use of these panels in Latin American populations are sparse. In parallel to emerging efforts aimed at describing the molecular characteristics of hereditary breast cancers in Latin America, there is a need to improve access to genetic testing and for the development of supporting infrastructures in cancer risk assessment, education, and genetic counseling [In recent years, a picture of the ountries ,75,196. unseling ,198.Risk prediction models that combine non-genetic and genetic risk factors were developed and are constantly being improved ,201,202.Progress in the discovery of population-specific breast cancer genetic risk variants in this region is limited by different factors, such as the slower incorporation of new genotyping and sequencing technologies, and the relatively small samples sizes partly due to the paucity of National Cancer Registries and the inconsistent collection of biospecimens  for research . On averThere are ongoing efforts to improve homogeneity of study design and increase sample size in studies in Latin America. In 2009, the Center for Global Health of the US National Cancer Institute (NCI) created the US-Latin America Cancer Research Network (LACRN), a collaborative management structure that includes Argentina, Brazil, Chile, Mexico, and Uruguay . In 2011To conclude, large collaborative international efforts that include knowledge and technology exchange and transfer will lead to studies with appropriate sample sizes and approaches to discover rare high-penetrance polymorphisms, as well as low-penetrance variants in Latin American women from different regions and with different ancestral proportions. Only then will we be able to provide appropriate genetic risk estimates and care to women of Latin American origin worldwide.


Despite efforts to increase the availability of clinical genetic testing and counseling for Hereditary Breast and Ovarian (HBOC)-related cancers, these services remain underutilized in clinical settings. There have been few efforts to understand the public’s use of cancer genetic services, particularly for HBOC-related cancers. This analysis is based on data from the 2015 National Health Interview Survey (NHIS), a U.S.-based nationwide probability sample, to better understand the public’s use of HBOC-related clinical cancer genetic services. Bivariate analyses were used to compute percentages and examine the associations of familial cancer risk for three genetic services outcomes . Multivariable logistic regression models were used to estimate the association of familial cancer risk and other demographic and health variables with genetic services. Most women (87.67%) in this study were at low risk based on self-reported family history of breast and ovarian cancer, 10.65% were at medium risk, and 1.68% were at high risk. Overall, very small numbers of individuals had ever had genetic counseling (2.78%), discussed genetic testing with their physician (4.55%) or had genetic testing (1.64%). Across all genetic services outcomes, individuals who were at higher familial risk were more likely to have had genetic counseling than those at lower risk , discussed genetic testing , and completed genetic testing . Those who perceived themselves as being more likely to develop cancer than the average woman were more likely to engage in genetic counseling , discuss genetic testing  or have had genetic testing . Personal cancer history was also a significant predictor of likelihood to have engaged in genetic services. Our findings highlight: (1) potential under-utilization of cancer genetic services among high risk populations in the U.S. and (2) differences in genetic services use based on individual’s characteristics such as self-reported familial risk, personal history, and beliefs about risk of cancer. These results align with other studies which have noted that awareness and use of genetic services are low in the general population and likely not reaching individuals who could benefit most from screening for inherited cancers. Efforts to promote public awareness of familial cancer risk may lead to better uptake of cancer genetic services.  BRCA1/2 pathogenic variant have substantially increased lifetime risks for breast and ovarian cancer compared to the general population [Women who carry a pulation ,4,5. In pulation ,9,10,11.BRCA1/2-related cancers, cancer genetic services remain underutilized in clinical settings [BRCA1/2 pathogenic variant have not yet been identified, and when they are, it is often within the context of a breast and/or ovarian cancer diagnosis [Despite well-defined strategies for screening among individuals who are at increased risk for settings ,14,15,16iagnosis . Geneticiagnosis ,19,20,21iagnosis . BRCA1/2 [BRCA1/2- or Lynch syndrome-associated cancers; however, since 2005, there have been substantial legal and social changes that would likely influence genetic service use  [BRCA1/2 pathogenic variant [Since 2005, the U.S. Preventive Services Task Force has recommended screening for unaffected  women with a strong family history of certain cancers to identify those who may be at increased risk for potentially harmful pathogenic variants in BRCA1/2 . It is rBRCA1/2 . Prior aion Act) . More re variant  and the  variant ,27,28,29 variant ,27,28,29 variant ,33,34,35BRCA1/2-related cancers. Therefore, the goal of this paper is to use the updated 2015 U.S. National Health Information Survey (NHIS) data to identify the likelihood that individuals have had genetic counseling, discussed genetic testing, or had genetic testing based on key demographic variables and familial risk of This secondary data analysis is based on data from the 2015 National Health Interview Survey (NHIS), which is a national probability sample survey that collects information about the United States population through annual household interviews . Due to Outcome Variables. Three outcome variables pertaining to genetic testing and counseling for cancer were included from the Cancer Control module. Participants were provided with a definition of genetic testing and counseling and were asked if they have ever had genetic counseling by responding to the question, “Have you ever received genetic counseling for cancer risk” (yes/no), ever discussed genetic testing for cancer by responding to the question, “Have you ever discussed the possibility of getting a genetic test for cancer risk with a doctor or other health care professional,” (yes/no), or ever had genetic testing for cancer by responding to the question, “Have you ever had a genetic test to determine if you are at greater risk of developing cancer in the future” (yes/no). Individuals only received the final question about whether they ever had genetic testing if they responded ‘yes’ to the previous question about ever discussing genetic testing for cancer with a provider. Independent Variables. Individual’s familial risk for BRCA1/2-related cancers (breast and ovarian) was estimated based on their reported number of first-degree female relatives  who had been diagnosed with BRCA1/2-related cancers  and the age of diagnosis . Familial risk was ranked as (1) “low risk” which included individuals with no first degree relatives with a history of breast or ovarian cancers, (2) “medium risk” that included women with at least one first-degree relative diagnosed with breast cancer at ≥50 years of age, or (3) “high risk” that included at least one first-degree relative diagnosed with breast cancer under the age of 50 and/or any family history of ovarian cancer [n cancer . These cn cancer . AdditioStatistical Analysis. We conducted a complete case analysis using the sample of women who answered questions about genetic testing and counseling. Women who responded to at least one of these three questions were included in the sample.We used weighted bivariate analyses to compute percentages and examine the associations of familial cancer risk with other characteristics and with each of the genetic testing and counseling outcomes. Weighted two-sample t-test (for age and education) and chi-square tests of independence  were used to determine statistical significance for each outcome. Multivariable logistic regression models were used to estimate adjusted odds ratios and corresponding 95% confident intervals for the association of familial cancer risk and covariates with each of the genetic testing and counseling variables. We controlled for all factors that were determined a priori to potentially affect genetic testing outcomes based on previous literature and model fit . Thus, tBRCA1/2-related cancers. Overall, very small numbers of individuals had ever had genetic counseling (2.78%), discussed genetic testing with their physician (4.55%) or had genetic testing (1.64%)  were at low risk , 10.65% were at medium risk , and 1.68% were at high risk (at least one first-degree relative diagnosed with breast cancer under 50 or any first-degree relatives with ovarian cancer) of developing  (1.64%) . Predictors of likelihood to have ever had genetic counseling  includedLevel of familial risk also influenced likelihood to have discussed genetic testing , with thThe final outcome of whether an individual has had genetic testing for cancer risk  was assoBRCA1/2-related cancers, our findings show potential underutilization in this nationally representative sample of females in the U.S. Higher levels of familial risk were associated with higher levels of genetic counseling, discussion of testing, and use of genetic testing; however, overall levels of engagement with genetic services were low. While over 12% of participants would have been considered eligible for genetic counseling and subsequent genetic testing based on family history, only a small subset received these services, suggesting that individuals at increased likelihood of HBOC are potentially not receiving appropriate follow-up services. These results align with previous reports that demonstrate low rates of awareness and utilization of counseling and testing, even among individuals at high risk of hereditary cancer [BRCA1/2 mutation carriers in the general population have been identified and a recent study found fewer than one-in-five at-risk breast or ovarian cancer patients have undergone genetic testing [Despite efforts to increase utilization of genetic services among individuals at risk for developing y cancer ,39,40 any cancer . It has  testing . We found significant differences across all genetic services outcomes based on individual’s perceived cancer risk. Individuals with higher risk perceptions may be more likely to engage with health professionals and be willing to discuss counseling and testing compared to those who are less worried . Indeed,not receive appropriate follow-up. Recent guidelines have suggested moving toward multigene panel testing for all breast cancer patients [BRCA1/2 mutations and underwent subsequent panel testing were found to have a pathogenic mutation in a breast cancer susceptibility gene [Our findings also suggest an association between personal cancer history and likelihood to engage in genetic services. This increased genetic service utilization among individuals with a personal history of cancer indicates a linkage between genetic service use and cancer diagnosis . While tpatients ,48. Thisity gene . FurtherSome of our results deviated from the literature, as we did not find significant differences in uptake of genetic counseling or genetic testing by race. Other studies have identified low levels of awareness and use of genetic counseling and testing among minority individuals. Efforts to expand genetic service use come in the context of widespread concerns that health benefits of genomic translation will not reach all those who could benefit and thus, will exacerbate health disparities ,51,52,53BRCA1/2-related cancers among women; however, BRCA1/2 mutations can also occur in men and recent results have demonstrated a gender gap in genetic testing [BRCA1/2 variants is even lower than what is reported in our results. Further, these data are cross sectional and self-reported, thus, we are unable to assess for causality and whether cancer risk predicted or preceded genetic counseling and testing uptake. The self-reported nature of data may limit findings, as these individuals may not know their full health history and there is opportunity for confusion about cancer types, especially among ovarian cancer, which may be mistaken for cervical and uterine cancer. In addition, the classification we used for familial cancer risk  was based on self-reported family history for BRCA1/2-related cancers. This approach was adapted from previous studies that have used NHIS [TP53, PTEN) and moderate penetrance genes  [While our results have important implications, this study is not without limitations. The Cancer Control Supplemental survey used for this analysis focused on  testing . Additiosed NHIS . However, CHEK2) ,60. GiveBRCA1/2-related cancers. In light of these limitations, our results have important implications at both the clinical and public health levels. Despite ongoing efforts to increase family health history knowledge and collection of family history at the individual and provider levels to improve risk stratification and referrals to counseling and testing, this study demonstrates that individuals at high risk may not be receiving appropriate information and referrals to genetic services. There is well-documented evidence indicating a lack of time spent on discussion of family health history and a wide range of variation in physician practice around collection of health histories ,62. FurtTelegenetic counseling service also holds the promise to expand cancer genetic services reach, especially among racial-ethnic minority groups, people in rural settings and with lower socioeconomic status ,77. The Findings of this study could inform future research and intervention elements such as strategies to improve collection of health history information, and ultimately improve appropriate referral and use of cancer genetic services for the benefit of all patients and their families.


Patients with a biopsy diagnosis of ductal carcinoma in situ (DCIS)might be diagnosed with invasive breast cancer at excision, a phenomenon known asunderestimation. Patients with DCIS are treated based on the risk ofunderestimation or progression to invasive cancer. The aim of our study was toexpand the knowledge on underestimation and to develop a prediction model.Population-based data were retrieved from the Dutch PathologyRegistry and the Netherlands Cancer Registry for DCIS between January 2011 andJune 2012.Of 2892 DCIS biopsies, 21% were underestimated invasive breastcancers. In multivariable analysis, risk factors were high-grade DCIS (odds ratio(OR) 1.43, 95% confidence interval (CI): 1.05–1.95), a palpable tumour , a BI-RADS (Breast Imaging Reporting and Data System) score 5 and a suspected invasive component at biopsy . The predicted risk for underestimation ranged from 9.5to 80.2%, with a median of 14.7%. Of the 596 invasive cancers, 39% hadunfavourable features.https://www.evidencio.com/models/show/1074).The risk for an underestimated diagnosis of invasive breast cancerafter a biopsy diagnosis of DCIS is considerable. With our prediction model, theindividual risk of underestimation can be calculated based on routinely availablepreoperatively known risk factors ( The standard treatment mightbe disproportionate for screen-detected DCIS patients who have a high chance thatthe DCIS would not even have been detected during theirlifetime.3 It has been estimated that between 14 and 53% ofDCIS progress into invasive breast cancer.5Patients with ductal carcinoma in situ (DCIS) are treated based on therisk of underestimation or progression to invasive cancer. The standard treatmentfor patients with a biopsy diagnosis of DCIS is wide local excision with radiationor mastectomy. Often a sentinel lymph node (SLN) biopsy is advised for axillarystaging.11 Active surveillance is based on the result of thebiopsy. By modelling of active surveillance of DCIS patients, the disease-specificcumulative mortality was related to underestimation.13 Underestimation is the phenomenon that theinvasive breast cancer is undetected at preoperative biopsy and only becomes evidentafter pathological examination of the excision material. The use of the SLN biopsycan also constitute overtreatment. The SLN biopsy is done if a mastectomy is chosen,and also for patients undergoing wide local excision who are at high risk of havingan underestimated invasive breast cancer.2 Thereported risk of underestimation varies from 14 to 43%15, and in a meta-analysis it was estimated to be25.9% : 22.5–29.5)16. These rates indicate that manypatients will still have the diagnosis of DCIS after examination of the excisionmaterial, and thus the SLN biopsy would not have been necessary.To address overtreatment, phase III trials investigate the safety ofactive surveillance of DCIS patients at low risk for developing or having invasivebreast cancer.27 Furthermore, these studies reported that therisk of underestimation was associated with age, palpability, histologic suspicionof invasion, image guidance method, biopsy device and other factors. An overview ofthe found risk factors for underestimation is given in Table 30.Knowledge on the risk of underestimation is important in selectinghigh-risk or low-risk patients for treatment or active surveillance. The mostfrequently reported risk factors for underestimation are DCIS grade and factorsfound with radiological diagnostic work-up, such as the size of the lesion, mass onmammography or ultrasonography, and the Breast Imaging Reporting and Data System(BI-RADS) score.31 Second, of the underestimated invasive breastcancers the information on unfavourable features is of interest; the reportedHer2Neu status is quite high23and the hormonal receptor statuses vary26.Besides the underestimation rate, other factors are useful for makinga treatment plan for a patient diagnosed at biopsy with DCIS. First of all, for someof these patients, no residual disease is found in the excision material; this isdefined as minimal-volume DCIS. A rate of 9.3% wasreported.The diversity of identified risk factors for underestimation hasresulted in differences between the clinical guidelines used in different countries.For example, according to the NICE guideline (United Kingdom) for the use of the SLNbiopsy, risk factors for underestimation are a palpable mass or extensivemicro-calcifications, while according to the Dutch guideline, these are age <55years, intermediate-grade or high-grade DCIS, a mass on mammography and a suspectedinvasive component based on biopsy. For active surveillance, the main criterion forpatient selection in low-risk DCIS trials are DCIS grade, and patients with mass orother relevant factors are excluded.The diversity in risk factors might be due to the study designs,since the investigated potential risk factors varied and many studies onunderestimation were single institution studies with limited number of cases.Information at the population level is lacking. In addition, there is hardly anydata on minimal-volume DCIS nor on the presence of unfavourable features of theunderestimated invasive breast cancer.The aim of our study was to expand the knowledge on underestimationof invasive breast cancer for patients with a biopsy diagnosis of DCIS in routineclinical practice in the Netherlands and to develop a prediction model based onpopulation data. We also analysed the association of predicted risk withminimal-volume DCIS and with the occurrence of unfavourable features of theunderestimated invasive breast cancer. The results could contribute to a treatmentplan that is both patient-specific and helps in reducing overtreatment.32 The NCR contains information that is collectedand coded by specially trained registration clerks from the hospitals’ patientfiles of every patient with cancer, after notification fromPALGA.33This study used retrospective data that were nationwide. Data werereceived from the Dutch Pathology Registry, which is managed by PALGA (thenationwide network and registry of histopathology and cytopathology in theNetherlands) and were matched with data from the Netherlands Cancer Registry(NCR), which is hosted by the IKNL (the Netherlands Comprehensive CancerOrganization). The Dutch Pathology Registry contains all the reports written bypathologists of material examined in all Dutch PathologyLaboratories.Lesions were selected from PALGA, since this study is based on thebiopsy diagnosis and the NCR registers the final diagnosis at excision.Histological breast biopsies were selected that were performed in the period 1January 2011 until 30 June 2012. The diagnosis should be carcinoma in situ, withno invasive cancer in the same biopsy, no lymph node metastases found preoperativeand also no melanoma in situ, Morbus Paget or Morbus Bowen. DCIS withmicro-invasion was not included, nor were intracystic carcinoma, lobular carcinomain situ and ductal hyperplasia lesions. Based on the PALGA conclusion (free textfield) information on the diagnosis, DCIS grade, suspected invasive component,synchronous contralateral tumour and ipsilateral history were coded. The data wereextended with those registered by the NCR: age, ipsilateral history, detectionmode, palpability, BI-RADS score, preoperative magnetic resonance imaging (MRI),multidisciplinary team meeting, type of first resection, nodal status, and of theinvasive cancers, the morphology, grade, the receptors ER, PR, Her2Neu and tumoursize. Lesions were excluded in case of incomplete registration, primarily noexcision of the lesion, a biopsy diagnosis that was inconclusive as to whether thelesion was benign or DCIS and in case of an ipsilateral history of DCIS orinvasive breast cancer.34 A synchronous contralateral lesion was definedas DCIS or invasive breast cancer in both breasts with a difference in incidencedate of <3 months. Underestimation was defined as invasive cancer ormicro-invasion found at excision after a biopsy diagnosis DCIS. Tumours weregraded according to the Bloom–Richardson grade or another equivalent method.Tumour size and nodal status were used to categorize the tumor node metastasis(TNM) stage.35 Underestimated invasive breast cancers werecategorized based on unfavourable features. In the Dutchguideline36, they were defined as features that, if present,would mean that systemic therapy would be recommended, because the absolute10-year mortality risk was at least 15%. These features of the invasive cancerswere:Her2Neu positive with size >5 mm.Age <35 years, except size ≤10 mm with grade I.Size >10 mm but ≤20 mm with grade II or III.Size >20 mm.Positive lymph nodes.Data were categorized as follows: the category detection modeconsisted of screen-detected DCIS (DCIS detected within 12 months after a positivemammography at the population-based screening programme) and otherwise detectedDCIS . DCIS grade was categorized into low, intermediate or high.If the tumour consisted of two different grades or if the grade was inconclusive,the highest DCIS grade was chosen. Suspected invasive component was coded ‘yes’ ifit was mentioned as such in the conclusion of the pathology report and if it wasnot refuted with potential additional staining. For the BI-RADS score, no subgroupinformation for score 4 was available.χ2test. The associations between potential risk factors were analysed with thePearson's χ2 test orthe Fisher's exact test. The risk for underestimation of invasive breast cancerwas analysed with logistic regression analysis. The threshold for significance ofrisk factors was the two-sided p value of 0.05.In this logistic regression, we only included characteristics that were known asindependent variables prior to operation: age, detection mode, palpability,BI-RADS score, DCIS grade and suspected invasive component at biopsy. The decisionto do a preoperative MRI and the type of first resection were not included in themodel, because no causal association with underestimation was expected. Next, toensure that all relevant variables were included in the prediction model, theindependent variables were chosen via stepwise backward selection with a p value threshold for elimination of p < 0.20. In the prediction model, age was testedmultiple times: continuously using both linear and quadratic terms anddichotomously with thresholds of 40, 45 and 55 years for comparison with previouspublications.21 Interaction was tested forcombinations that were clinically the most plausible: suspected invasive componentand DCIS grade, age <45 years (based on cut-off age in active surveillance) incombination with BI-RADS score, or palpability, or DCIS grade. To account formissing data, multiple imputation with fully conditional specification was used inthe multivariable logistic analysis. Twenty imputed data sets were generated, andthe results were pooled according to Rubin’s rules. Based on the imputed data, aformula was defined to predict the risk. Finally, internal validation of the modelwas performed with bootstrap repetitions (200 times). The logistic regressionmodel was evaluated with the area under the curve (AUC) of the receiver operatingcharacteristic (ROC). Based on the predicted risks, patients were divided intofive subgroups, and the association with minimal-volume DCIS and unfavourablefeatures was analysed with the p-trend test forproportions. The analyses were done with STATA statistics/data analysis, version13.1, StataCorp, Texas and in R, with the rms package for the evaluation of thepredictive performance and the mice package for multiple imputation.The data were analysed to investigate associations and to develop aprediction model. First, the distribution of patient characteristics and potentialrisk factors was compared between patients with and without underestimatedinvasive breast cancer for the non-missing values, using the Mann–Whitney test orthe Pearson's Of 3281 lesions that were selected with a preoperative biopsydiagnosis DCIS, 64 (2.0%) were excluded because they were not registered in the NCR,and 15 (0.5%) because registration was incomplete. In addition, to answer theresearch question accurately, more were excluded: 60 (1.8%) that did primarily notundergo excision, 143 (4.4%) for which the biopsy diagnosis was inconclusive and 107(3.3%) with an ipsilateral history of DCIS or invasive breast cancer, resulting in2892 DCIS diagnoses included in the study. Of these, 379 (13%) had missing data forone or more potential risk factor: 148 for palpability, 223 for BI-RADS score, 84for DCIS grade and 81 for detection mode.p = 0.001). Of the intermediates, 13% were lowto intermediate or consisted of both low-grade and intermediate-grade DCIS, 21% wereintermediate to high grade or consisted of both intermediate-grade and high-gradeDCIS. The underestimation rate was 21% on average for all cases, 26% fornon-screen-detected lesions, 36% for palpable lesions, 41% for BI-RADS score 5 and23% for high-grade DCIS . The risk factors with thegreatest differences in underestimation rate for subgroups were palpability, with a20% higher rate for palpable than for non-palpable lesions, BI-RADS score, with a25% higher rate for BI-RADS score 5 than for score 3, and suspected invasivecomponent, with a 31% higher rate for suspected invasive component than for none. Of596 invasive breast cancers, 47 were T1mi and 207 were T1a. The underestimation ratewhen filtering out all lesions of 5 mm or smaller was 11.8% (n = 342).Of the 2892 DCIS diagnoses at biopsy, 596 (20.6%) wereunderestimated, as the diagnosis was invasive breast cancer at excision.Table Table For each of the 2892 DCIS, the risk of an underestimated invasivebreast cancer was calculated based on the prediction model with the followingformula:https://www.evidencio.com/models/show/1074.For example, the predicted risk is calculated as follows for ascreen-detected DCIS which is non-palpable, has a BI-RADS score 4, anintermediate-grade and no suspected invasive component:score = −2.1131 + 0.1555 × 0 + 0.7985 × 0 − 0.1464 × 0 + 0.8589 × 0 + 0.3111 × 1 + 0.3571 × 0 + 1.3445 × 0 = −1.802,andThe predicted risks ranged from 9.5 to 80.2%, the mean was 20.6% andthe median was 14.7%. The predicted risk for underestimation was on average 27.4%for the biopsy of DCIS that were underestimated invasive breast cancers, whereas itwas on average 18.8% for the biopsy of DCIS that also had the DCIS diagnosis atexcision. The predicted risks for each combination of risk factors are shown insupplement c-index) of theROC was 0.668 and the AUC, corrected for optimism by bootstrapping, was 0.661. TheAUC for a model based only on lesions >5 mm was 0.69.The ability of the model to separate DCIS as diagnosis after excisionfrom underestimated invasive breast cancer is shown in Fig. Based on the predicted risks, the DCIS biopsies were divided intofive subgroups; the characteristics of each subgroup are shown in Table p < 0.001  orinitial treatment can be started (with an increased risk of underestimation). Also,for DCIS grade, other studies might have used different grading systems. Anotherlimitation is that results of observational studies are difficult to compare becauseof differences in diagnostic work-up, differences in major selection criteria, suchas the presence of micro-invasion, differences in investigated risk factors andassociations between the investigated risk factors. Our dataset did not provideinformation on the number of biopsies nor on the biopsy device, and hence the amountof tumour taken at biopsy was not known. Some other factors were not availableeither, such as the presence of comedo-necrosis, the breast density, the visibilityof the lesion on ultrasound, the presence of mammographic mass or the size of thelesion seen on the mammogram.The model in this study is based on a large dataset that is based onnationwide Dutch data, and it demonstrated the association of risk forunderestimation with minimal-volume DCIS and unfavourable features of invasivecancer, which makes the results valuable. The prediction model could be improved byadding additional data; the most interesting targets of investigation for futureresearch are the biopsy type and mammography-related data: BI-RADS score 4subcategories, the underlying reasons for a BI-RADS score (such as mass), size ofthe lesion and presence of residual mammographic abnormalities after biopsy.Furthermore, the prediction model should be validated externally.Our results demonstrated that the risk for an underestimateddiagnosis of invasive breast cancer after a diagnosis of DCIS at biopsy isconsiderable. Of these invasive breast cancers, two-fifths has unfavourablefeatures. With our prediction model, the individual risk of underestimation can becalculated based on routinely available preoperatively known risk factorsSupplementary info 1 - associations risk factorsSupplementary info 2 - predicted risksSupplementary info 3 - calibration plotSupplementary info 4 - tumour characteristics


Smoking is one of the well-established risk factors for gastric cancer incidence, yet whether men are more or equally susceptible to gastric cancer due to smoking compared with women is a matter of controversy. The aim of this study was to investigate and compare the effect of sex on gastric cancer risk associated with smoking.We conducted a systemic literature search in MEDLINE, EMBASE, and the Cochrane CENTRAL databases to identify studies published from inception to December 2018. We included prospective observational studies which reported effect estimates with 95% confidence intervals (CIs) for associations of current or former smokers with the incidence of gastric cancer by sex. We calculated the ratio of relative risk (RRR) with corresponding 95% CI based on sex-specific effect estimates for current or former smokers versus non-smokers on the risk of gastric cancer.P = 0.019). Furthermore, there was no significant sex difference for the association between former smokers and gastric cancer risk . However, the result of sensitivity analysis indicated the pooled result was not stable, which was altered by excluding a nested case-control study .We included 10 prospective studies with 3,381,345 participants in our analysis. Overall, the summary RRR  for gastric cancer risk in current smokers was significantly increased compared with non-smokers  contains supplementary material, which is available to authorized users. Helicobacter pylori infection, coffee, dairy products, red meat consumption, tobacco smoking, radiation, high body mass index, and family history [Gastric cancer is the fifth most common cancer and the third leading cause of cancer mortality worldwide, despite its decreasing incidence in recent decades , 2. More history –8. TherePrevious studies have indicated that environmental factors could affect gastric cancer risk more prominently than genetic factors –11. SeveThis systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement issued in 2009 . RelevanTwo authors independently performed a literature search and study selection, and disagreements between two authors were settled by a discussion in a group until a consensus was reached. A study was deemed eligible if it met the following inclusion criteria: (1) the study design was a prospective observational study; (2) the study evaluated the association of smoking status with gastric cancer risk; and (3) the associations between smoking status and gastric cancer risk in men and women were both reported.Two authors independently collected and extracted data from the included studies, and disagreements were resolved by a group discussion. The data collected from the included studies contained the following items: first author, publication year, country, sex, sample size of men and women, mean age for men and women, number of participants who had never smoked (non-smokers) for men and women, number of former smokers in men and women, number of current smokers in men and women, follow-up duration, reported outcomes, and adjusted factors.We assessed the methodological quality of the included studies using the Newcastle-Ottawa Scale (NOS) , which hThe associations between smoking status and gastric cancer risk in men and women were determined based on the relative risk (RR), hazard ratio (HR), or odds ratio (OR), and the 95% confidence intervals (CIs) in each individual study. HR is considered equivalent to RR in prospective observational studies, and OR could also be assumed to be equivalent to the RR due to the low incidence of gastric cancer. We calculated the ratio of RRs (RRR) for current or former smokers versus non-smokers and the risk of gastric cancer based on sex-specific RRs in individual studies . We used2 and Q statistics, and P values < 0.10 mean significant heterogeneity [P values were two-sided with significance defined as P < 0.05. Statistical analyses were conducted using STATA software .Heterogeneity among studies was shown by the Iogeneity , 19. A sogeneity . The potogeneity . Subgrouogeneity , 23. AllA total of 1517 records from the initial search were identified, including 691 from MEDLINE, 757 from EMBASE, and 69 from the Cochrane CENTRAL. After discarding 1423 irrelevant or duplicate studies, 94 potential studies were selected for further reading. After detailed evaluating, 10 prospective observational studies were selected into the quantitative analysis –33. The Ten studies with a total of 3,381,345 participants were included in our analysis. Among the studies, nine were prospective cohort studies , 29–33 aP < 0.001; Fig. P = 0.010; Fig. P = 0.019; Fig. 2 = 52.6%; P = 0.025). The result of the sensitivity analysis indicated that the sex differences in the association between current smokers and gastric cancer were affected by the exclusion of multiple studies due to the small numbers of cohorts included (Table P = 0.001), regardless of follow-up duration , when the study reported gastric cancer mortality , when the study did not adjust for BMI , when the study did not adjust for alcohol consumption , and when the study had a NOS score of 7 or 8 .All included studies reported sex differences in the association between gastric cancer risk and current smokers compared with non-smokers. We noted current smokers were associated with higher risk of gastric cancer when compared with non-smokers in men . Following the result of the sensitivity analysis, we excluded the study by Lindblad et al. [P = 0.002; Table P = 0.019; Table P = 0.038), when the study reported gastric cancer mortality .A total of 9 studies reported sex differences in the relation between gastric cancer risk in former smokers compared to non-smokers. The summary result indicated former smokers were associated with an increased risk of gastric cancer in men  and women  were associated with a significantly increased risk of gastric cancer when compared to non-smokers . FurtherThe summary RRR indicated that male current smokers had a greater risk of gastric cancer than women. However, several studies included in our study reported inconsistent results. Lindblad et al. indicated that female current or former smokers were significantly associated with a higher risk of gastric cancer than non-smokers, while this association was not statistically significant in men . The reaThe findings of the subgroup analyses indicated that the sex differences in gastric cancer risk for current smokers might be affected by country, reported outcomes, whether BMI or alcohol were adjusted for, and study quality. Male former smokers were associated with a higher risk of gastric cancer than female former smokers when the study was conducted in Asia, the outcome was gastric cancer mortality, the study did not adjust for BMI or alcohol consumption, and the study had high study quality. However, female former smokers were associated with a higher risk of gastric cancer than men when the included studies had lower study quality. One possible reason for the locational difference could be that different types of tobacco available between Asian and Western countries, which could have different effects on gastric cancer risk. Furthermore, men might smoke more cigarettes and have a longer duration of smoking than women, which might affect the gastric cancer mortality. Finally, the findings of the subgroup analyses may be variable due to the small cohorts included for several subsets. Therefore, a synthetic and comprehensive review was provided in this study.We had three strengths in our study that should be highlighted. First, only prospective observational studies were included, which should eliminate the selection and recall biases inherent in retrospective observational studies. Second, the large sample size allowed us to quantitatively assess the association of smoking status and risk of gastric cancer, thus our findings are potentially more robust than the individual studies. Third, sex differences in the associations between smoking status and the risk of gastric cancer were directly compared among individual studies.Helicobacter pylori infection is an important factor which is associated with a higher risk of gastric cancer, but none of the included studies adjusted for Helicobacter pylori and corresponding treatment strategies [The limitations of our study were as follows: (1) the adjusted models were different in the included studies, and these factors might play essential roles in the development of gastric cancer; (2) the history of rategies ; (3) theThe results of this study suggested that current smoking might have a more important effect on gastric cancer risk in men than women, while no sex differences were found for the association between former smokers and gastric cancer risk. Furthermore, potential sex difference for the association between former smokers and gastric cancer risk was observed through sensitivity analysis. In addition, this significant sex-difference mainly focused on gastric cancer mortality, while no sex-difference of current or former smoking on gastric cancer incidence. Several factors might affect this sex difference in the risk of gastric cancer, and future studies should focus on other impact factors to analyze the sex difference of gastric cancer.Additional file 1:Supplemental 1. Meta-regression analyses for the sex difference of the association between current or former smokers and gastric cancer based on follow-up duration. (DOC 6972 kb)