From BMD to breast cancer, no significant association was found (FDR > 0.05). The mediating MR analysis showed that Higher free testosterone (FT) only mediated the causal relationship between breast cancer and HE-BMD by 2.9%; both ER+ type and FT were independent factors of HE-BMD . Higher FT could increase the risk of breast cancer (FDR = 1.21 × 10−3) as could total testosterone (TT) (FDR = 5.81 × 10−3). Similarly, higher FT could increase the risk of ER+ subtype (FDR = 2.51 × 10−6) as could TT (FDR = 5.55 × 10−4). These results indicate that BMD is not a risk factor for breast cancer but breast cancer and its ER+ subtype are risk factors for BMD loss. Furthermore, higher FT and TT levels are associated with both an increased incidence of breast cancer and increased bone density.The purpose of this study was to verify whether there is a causal relationship between breast cancer and bone mineral density (BMD). Summary statistics for exposures and outcomes were obtained from corresponding genome-wide association studies. The bidirectional and multivariate mediated Mendelian randomization (MR) analyses were performed. In the bidirectional MR analysis, breast cancer might reduce the BMD of the heel (HE-BMD) (FDR = 1.51 × 10 Osteoporosis is the most common in postmenopausal women and is characterized by low bone density, which increases the risk of fractures3. So the risk of breast cancer and osteoporosis increases as women get older. A recent study compared the bone mineral density (BMD) of women newly diagnosed with breast cancer with that of women without breast cancer. It demonstrated that women with newly diagnosed breast cancer have higher BMD than women with similar characteristics but without breast cancer, suggesting that higher BMD may be a risk factor for breast cancer4. Similarly, a study of women in South Korea and a study of women in southern Israel both found that women who have higher rates of breast cancer also have higher bone density6. However, these studies are observational, and the causal relationship between breast cancer and BMD has not been elucidated—do women with breast cancer have higher bone density? Or does higher bone density increase the risk of breast cancer? Other relevant research results are different; they show that higher or lower bone density is not associated with breast cancer and that BMD cannot predict the risk of breast cancer9.Breast cancer is one of the most common malignant tumors that harm women's health, and its incidence increases gradually with age. Nearly half of newly diagnosed breast cancer cases are in patients aged 65 or older11. Higher levels of testosterone and oestradiol have been associated with an increased risk of breast cancer in both pre- and postmenopausal women as well as women of different ethnic groups and have been more commonly reported in postmenopausal populations16. Higher testosterone and oestradiol levels can increase bone density and reduce the risk of osteoporosis19. Are hormone levels a potential link between osteoporosis and breast cancer? Since the causal relationship between osteoporosis and breast cancer is still unclear, and to explore the role of hormone levels, bidirectional, multivariate mediated Mendelian randomization (MR) methods were used in this study. Testosterone is an important female hormone that acts as both an essential precursor for estradiol biosynthesis and an androgen. Therefore, this study chose testosterone as the research object of hormone level. MR, an epidemiological causal inference method, is used to evaluate the potential causal influences of risk factors on outcomes by using genetic instrumental variables (IVs) and can reduce the bias caused by confounders20. Bidirectional MR can assess whether there is reverse causality between exposure and outcome, that is, whether outcome causes exposure. Multivariate mediated MR are used to investigate whether there is a mutual mediating effect between multiple factors on the same outcome. Heterogeneity, pleiotropy, and horizontal pleiotropy were used to assess the sensitivity of the results. There may be heterogeneity in the instrumental variables of different analysis platforms, experiments and populations. If instrumental variables do not directly affect the results through exposure factors, there will be pleiotropy. These may affect the robustness of MR results. The purpose of this study was to use MR methods to explore whether there is a causal relationship between breast cancer and BMD and whether hormone levels mediate the relationship between the two.There are many risk factors associated with breast cancer and BMD. Hormone levels may play an important role in breast cancer and osteoporosis21. The study reported genome-wide association results from 122,977 breast cancer patients of European ancestry and 105,974 controls as well as 14,068 breast cancer patients of East Asian ancestry and 13,104 controls. Only the subjects with European ancestry were included in our MR study. Analysis statistics from OncoArray and iCOGS were adjusted for country and study. For the OncoArray analysis, statistics were adjusted for country and 10 principal components. In our MR analysis, we included single nucleotide polymorphisms (SNPs) associated with breast cancer and its subtypes, oestrogen receptor-positive/negative (ER+/ER−), as IVs of exposure in European women, and they were also used as outcomes in the bidirectional MR analysis.The instrumental variables (IVs) for breast cancer were extracted from the Breast Cancer Association Consortium (BCAC), which was a large-scale meta-analysis conducted using iCOGS, OncoArray and nine of the GWAS datasets22. The other GWAS included 426,824 European individuals for heel BMD (HE-BMD), and the covariates were sex, age and genotype23.BMD is an important basis for the clinical diagnosis of osteoporosis. In this study, BMD was used as the outcome of MR analysis and as exposure in bidirectional MR. The GWAS summary statistics related to BMD were selected from two large meta-analyses and assessed at four different bone sites. One GWAS included 53,236 individuals of European ancestry, including lumbar spine BMD (LS-BMD), femoral neck BMD (FN-BMD), and forearm BMD (FA-BMD), and the covariates were sex, age and weight24. The participants were 425,097 Europeans with sex-hormone binding globulin (SHBG), total testosterone (TT), and oestradiol statistics and 382,988 Europeans with free testosterone (FT) statistics. The researchers adjusted for age and BMI and disaggregated by sex. Since most of the women in the study were postmenopausal and their oestrogen levels were undetectable, the analysis was limited by a bias towards detecting age at menopause-associated loci. Therefore, oestradiol level assessment in women was not considered. In our MR study, the FT and TT of women were included as the study objects of hormone levels.The GWAS summary statistics of hormone levels were obtained from a recent GWAS, which was a large-scale meta-analysis conducted using the UK BiobankSeveral observational studies have found an association between breast cancer and bone mineral density risk. Three reasonable hypotheses can be made about this association: (1) breast cancer is a risk factor for BMD change; (2) BMD is a risk factor for breast cancer; and (3) whether hormone levels play a mediating role between breast cancer and BMD.A bidirectional MR was used to test the first two hypotheses. For the first hypothesis, we first selected significantly correlated SNPs from GWAS results of breast cancer and ensured that these SNPs were independent of confounders and BMD. BMD was used as the outcome, and relevant SNP information was extracted from the corresponding GWAS data. BMD was used as exposure in the second hypothesis. SNPs significantly related to BMD were identified from GWAS to ensure that these SNPs were independent of confounders and were not directly related to breast cancer. Breast cancer was taken as the outcome. Bidirectional MR analysis was performed to clarify the causal relationship between breast cancer and BMD. A bidirectional MR analysis flow chart is shown in Fig. 25. For the proportion of intermediary factors, refer to the research method of Xu et al., first calculate the indirect effect, and then divide by the total effect26. The effect of exposure on mediating factors was determined as β1; After correcting for the effect of exposure, the effect of mediators on the results was β2; After correcting the mediating effect, the effect of exposure on the results was β3. β1 × β2 was the indirect effect and β3 + β1 × β2 was the total effect26.For the third hypothesis, the multivariate mediated MR analysis was performed to determine whether hormone levels played a role in the relationship between BMD and breast cancer−8) and had a minor allele frequency > 0.01 were identified in GWAS databases and used as IVs. The condition r2 = 0.01 and KB = 5000 was used to remove SNPs with linkage disequilibrium (LD). The phenotypic variation explained by SNPs was calculated as follows: R2 = 2 × beta2 × (1 − EAF) × EAF/SD2, with EAF = effect allele frequency and beta = the effect of each SNP on the exposures27. The F statistic (F = beta2/se2) was used to test the strength of the association between these SNPs and the exposure factors. SNPs with strong statistical power (F statistics > 10) were included. These screened SNPs were extracted from the outcome-related GWAS databases. Then, the effect value directions of the exposure data and the outcome data were unified, and the SNPs that were palindromic with the intermediate allele frequency > 0.45 and < 0.55 were removed28. And SNPs from the exposure data were discarded when they could not be found in the outcome data.SNPs significantly associated with exposure that achieved genome-wide significance  based on the Benjamini and Hochberg method was used to adjust the P values for multiple testing. The mRnd (https://cnsgenomics.shinyapps.io/mRnd/) was adopted to calculate the statistical power of MR.The inverse-variance weighted (IVW), weighted-median28, “MR-PRESSO”31, and “MendelianRandomization”33 packages.All Mendelian randomization analyses were performed in R software version 4.1.1 using the “TwoSampleMR”Ethical approval was not required because this study used the data from publicly available databases.The number of SNPs selected as instrumental variables that were significantly correlated with exposure ranged from 4 to 1079. Their explained variances varied from 2.5 to 31.7%. The F statistics for each SNP and the general F statistics were all greater than 10 (Table −4) as was the ER+ subtype  . No causal relationship was found between breast cancer, its subtype and BMD in other sites—LS, FN, FA. Heterogeneity was found in Mendelian randomization of breast cancer, ER+ subtype to HE-BMD, LS-BMD and FN-BMD. When heterogeneity existed in sensitivity analysis, the statistics of weighted median method were in the same direction as that of IVW models, and the weighted median method was selected as the main statistical effect. Horizontal pleiotropy was found for the ER− subtype to HE-BMD. The MR-Egger result was adopted as the main effect size. The original results of IVW, weighted-median, and MR-Egger between breast cancer and BMD can be found in Supplemental Table In the MR analysis from breast cancer to BMD, there was an inverse causal relationship between breast cancer, its ER+ subtype and HE-BMD. Breast cancer might reduce HE-BMD and was recognized as a risk factor for osteoporosis  Fig. . The ER−In the MR analysis from BMD to breast cancer, no significant association was found ; similar results could be seen with TT  . The mediating MR analysis showed that FT only mediated the causal relationship between breast cancer and HE-BMD by 2.9%. The effect of breast cancer and its ER+ subtypes adjusted FT on HE-BMD was shown in Fig. In the MR analysis of hormone levels to BMD, there was a positive causal relationship between FT, TT and HE-BMD. Higher FT could increase HE-BMD and was considered a protective factor for osteoporosis  Fig. . FT and −3) as could TT   as could TT   Fig. . Similar−4) Fig. . FT and The statistical power for exposure to FT and TT to outcomes HE-BMD, breast cancer, and ER+ were all 100%; however, the statistical power of exposure to breast cancer and ER+ in HE-BMD outcomes was 74% and 69%, respectively.34. BMD in the hip and lumbar spine continues to decline after initiation of aromatase inhibitor therapy in breast cancer patients, and annual bone loss levels are elevated in women younger than 55 years of age35. A prospective cohort study found that young breast cancer survivors have an increased risk of developing osteoporosis compared with women without cancer36. Osteoporosis occurs during treatment and extends beyond breast cancer treatment, which is a long-term effect, but it can also occur after the end of breast cancer treatment as a late effect37. Osteopenia and osteoporosis in breast cancer survivors have been widely reported in clinical observational studies. Adjuvant chemotherapy and hormone therapy may be important causes of bone loss in breast cancer patients. Incidentally, hormone therapy is the main treatment for the ER+ subtype of breast cancer. In this MR analysis, breast cancer and ER+ subtypes were risk factors for decreased bone mineral density.Our MR study explored the causal relationships between breast cancer and BMD. In bidirectional MR, breast cancer and its ER+/ER− subtypes were used as exposure, and a negative causal relationship between breast cancer, ER+ subtype and HE-BMD was found. The incidence of breast cancer and its ER+ subtype may lead to a decrease in bone mineral density, which is consistent with many observational studies, although the statistical power of this causal relationship is insufficient. Several observational studies have explored changes in bone mineral density in breast cancer survivors. During 3 years of follow-up, women diagnosed with breast cancer lost up to 6.8% of their BMD. Chemotherapy and premenopausal status may be important risk factors for bone loss40. However, bone mineral density was not found to be a risk factor for breast cancer in ourr MR Study. The same results are consistent with a recently published Mendelian Randomized study of bone density and breast cancer risk. The results of this study also provide no evidence to support a causal association between BMD and breast cancer, while considering that the association found in observational studies could be explained by polymorphic genetic variants that contribute to the pathology of osteoporosis and breast cancer41. Elevated hormone levels, including levels of oestradiol and testosterone, have been found to be associated with BMD and breast cancer in several studies42. So we further explored whether testosterone level mediate the relationship between breast cancer and BMD. Multivariate mediated MR studies had found that the effect of TT on HE-BMD was largely mediated by FT. The mediating effect of FT on the causal effect of breast cancer on HE-BMD was only 2.9%, which was equivalent to almost no mediating effect. There was no mediating effect of FT in the causal effect of ER+ subtype of breast cancer on HE-BMD, and both FT and ER+ subtype of breast cancer were independent risk factors for HE-BMD. BMD is related to many factors, including alcoholism, body mass index, glucocorticoids, sex hormone levels, and thyroid and parathyroid function44. Novel mechanisms involved in the pathological process of osteoporosis have also been found, including the roles of the gut microbiome, autophagy, iron balance and cellular senescence3. This suggests that there are many other factors that may be associated with BMD, however, testosterone level as one of them play little mediating role in the association between breast cancer and BMD. National Health and Nutrition Examination Survey (NHANES) looked at the association between testosterone levels and BMD in middle-aged and older women from 2011 to 2016. The study, which included 2198 female participants, found a positive correlation between testosterone levels and lumbar bone density across subgroups of race and income45. A study of older postmenopausal women, in whom oestrogen levels were low, found that TT is directly correlated with the BMD of the LS and hip bone, and the FT level is positively correlated with the BMD of the hip46. Consistent with the above observational findings, our MR Study also supported the positive correlation between testosterone levels and BMD in women, and we also found a positive causal relationship between testosterone levels and the prevalence of breast cancer and its ER+ subtype. In fact, the relationship between testosterone levels and breast cancer has also been observed in prospective studies. A prospective analysis of testosterone levels and the risk of 19 types of cancer in men and women found that both FT and TT were risk factors for endometrial and breast cancer in the female population47. The UK Biobank included 58,629 normal-weight postmenopausal women whose increased risk of breast cancer was associated with relatively high levels of testosterone48. Therefore, testosterone levels have been found to have a causal relationship with both BMD and breast cancer. This relationship may explain why some observational studies have found an increase in BMD in newly diagnosed breast cancer patients6 but no causal relationship between increased BMD and breast cancer incidence. On the other hand, our MR study found that breast cancer and its ER+ subtype were potential adverse factors for BMD, while there was a positive causal relationship between testosterone level and breast cancer and its ER+ subtype. This also suggests that elevated testosterone levels may indirectly cause bone density loss while promoting breast cancer.In several observational studies, women newly diagnosed with breast cancer, prior to any antitumor therapy, have been found to have higher BMD than women without breast cancer, and BMD is positively correlated with the incidence of breast cancer. High BMD is considered a biomarker of breast cancer riskHowever, our MR Analysis also has some limitations. The polymorphism of SNPs selected as instrumental variables is a major concern. If SNPs influence multiple outcomes through independent factors, it is difficult to prove that exposure-mediated inference is unbiased. Therefore, the MR-Egger intercept and MR-PRESSO methods were used in our study to detect the level pleiotropy, in order to reduce bias. Secondly, we used the summary data of existing GWAS. Therefore, when BMD is used as the outcome, it cannot be stratified according to gender, which may lead to bias in the results. Finally, the results of this study only apply to participants of European ancestry, and further verification is needed in other populations of ancestry.In conclusion, BMD is not a risk factor for breast cancer but breast cancer and its ER+ subtype are risk factors for BMD loss:—breast cancer might reduce HE-BMD and is considered a risk factor for osteoporosis, as is the ER+ subtype;—there is no causal relationship between BMD and breast cancer, nor is BMD mediated by FT and TT. Furthermore, higher FT and TT levels are associated with both an increased incidence of breast cancer and increased bone density:—FT and TT levels in women are risk factors for breast cancer and its ER+ subtype which have been found to be risk factors for osteoporosis (underlined above);—higher FT and TT levels increase HE-BMD and are considered protective factors for osteoporosis. So, FT and TT levels are considered to be risk factors for osteoporosis (indirectly) as well as protective factors for osteoporosis (directly).Supplementary Tables.


The aim of this study is to evaluate the efficacy, feasibility and acceptability of a co-designed lifestyle-focused text message intervention (EMPOWER-SMS) for breast cancer survivors’ self-efficacy, quality of life (QOL), mental  and physical  health.Single-blind randomised controlled trial (1:1) comparing EMPOWER-SMS to usual care at 6-months (intention-to-treat). Setting: public Breast Cancer Institute . Eligibility criteria: adult (> 18 years) females, < 18-months post-active breast cancer treatment (stage I-III), owned a mobile phone, written informed consent. Primary outcome: Self-Efficacy for Managing Chronic Disease Scale at 6 months. Process data: message delivery analytics, cost, and post-intervention survey.N = 160; mean age ± SD 55.1 ± 11.1 years) were recruited 29th-March-2019 to 7th-May-2020 and randomised (n = 80 EMPOWER-SMS: n = 80 control). Baseline mean self-efficacy was high . Six-month follow-up: no significant differences between groups for self-efficacy , QOL, mental health, physical activity, or BMI. Significantly less EMPOWER-SMS participants missed ≥ 1 endocrine therapy medication doses compared to control . Text messages were delivered successfully , costing $13.62USD/participant. Participants strongly/agreed EMPOWER-SMS was easy-to-understand , useful , motivating for lifestyle change  and medication adherence .Participants (EMPOWER-SMS was feasible, inexpensive, acceptable for delivering health information to breast cancer survivors between medical appointments, with minor improvements in medication adherence.Text messages offer a feasible strategy for continuity-of-care between medical appointments.The online version contains supplementary material available at 10.1007/s11764-022-01209-9. Breast cancer is the most commonly diagnosed cancer among women worldwide and five-year survival rates are high (85–90% in high-income countries) . HoweverMobile health  interventions  are strategies for providing health information remotely . The mosOur team co-designed the EMPOWER-SMS text message program with breast cancer survivors, health professionals and researchers, which aims to improve breast cancer survivors’ health self-efficacy, quality of life (QOL), mental  and physical  health . We hypohttp://www.who.int/trialsearch/Trial2.aspx?TrialID=ACTRN12618002020268, 17-December-2018). University of Sydney was the study sponsor.The study protocol is published . BrieflyParticipants were recruited from the Westmead Breast Cancer Institute in Western Sydney, Australia that serves a culturally and socioeconomically diverse population. Inclusion criteria: adult (> 18 years) females, diagnosed with early-stage (0–III) breast cancer, within 18 months of finishing active breast cancer treatment  and owned a mobile phone. Exclusion criteria: diagnosed with metastatic breast cancer or insufficient English to provide consent.The control group received usual medical care according to the breast cancer institute, which included access to breast care nursing and allied health support . Participants received one ‘welcome’ text message at baseline, containing their group allocation, and one ‘follow-up interview reminder’ text message at six-months.EMPOWER-SMS aimed to provide supportive health education and was co-designed by breast cancer survivors, health professionals and researchers . ParticiStudy visits were in-person at baseline and 6 months . BrieflyBMI , body fat percentage and skeletal muscle mass measured using the Seca medical Body Composition Analyser   and waisQOL  . Two queBrief Illness Perception Questionnaire [BIPQ]  is scoreA mean difference of 1 (SD 2.05) on the Self-Efficacy for Managing Chronic Disease Scale (6 items) between EMPOWER-SMS and control at 6 months was considered clinically meaningful . A totalParticipants were randomised in a 1:1 (EMPOWER-SMS: control) allocation ratio, using a secured central computer-based randomisation service . Group allocation was automatically concealed using computer software (Research Electronic Data Capture [REDCap]), which revealed codes ‘Group A’ or ‘Group B’ to the researcher, maintaining researcher blinding. A subsample of 32/160 (20%) participants were randomised to wear an accelerometer, stratified by group , which notified researchers using a computer-generated notification. On the Monday after enrolment, the blinded researcher submitted the ‘Group A’ or ‘Group B’ allocation into the text message software, which automatically sent the ‘welcome’ text message containing participants’ group allocation (EMPOWER-SMS or control). Participants were instructed not to share their group allocation with the research team. A blinded researcher conducted the follow-up interview.Analyses were pre-specified and performed according to the intention-to-treat principle by a blinded statistician . PrimaryTo validate the GPAQ, metabolic equivalents (MET) minutes/day for moderate-to-vigorous physical activity (MVPA) were compared between the self-reported and accelerometer-assessed physical activity. Freedson and colleagues (1998)  cut-poinAutomated text message delivery software (April 2019–November 2020) collected the number of text messages that were sent, delivered successfully or unsuccessfully (‘bounced’), resulted in an ‘opt-out’ or a reply . ‘Reactions’ are when a participant clicks on a text message, then clicks that they ‘liked’, ‘loved’ or ‘laughed at’ the message.Text message delivery data were used to estimate the cost per person of intervention delivery. Total staff time dedicated to intervention monitoring was estimated.End-of-study feedback survey data were collected, including 13 questions: ten 5-point Likert-scale items (1 = strongly disagree to 5 = strongly agree) and three yes/no. Question topics included participants’ perceived acceptability and usefulness of repeated text messages, delivery timing, and content suitability for breast cancer survivors.n = 78) or control (n = 78) groups and were included in the analysis. At 6 months, 14/156 (9.0%) participants did not complete the follow-up visit and 2/78 (2.5%) discontinued the intervention  and 160 enrolled and were randomised . A sensitivity analysis using complete case analysis was conducted to confirm the results, as there was more than 5% missing (completely-at-random) data and revealed no significant differences between EMPOWER-SMS and control groups . Overall, few participants missed ≥ 1 doses of endocrine therapy medication. However, there was a significant difference between groups, with EMPOWER-SMS participants missing less doses than control . There were no other significant differences between groups (Table Self-efficacy data were available for 138/158 (87.3%) randomised participants . There were no significant differences in self-efficacy at 6 months between EMPOWER-SMS and control groups  and was over-estimated in the EMPOWER-SMS group  and control group . Wilcox rank sum test found that accelerometer METS did not differ between groups .Accelerometer data were available for 26/32 (81.2%) participants at baseline  and 20/32 (62.5%) participants at follow-up . Overall, self-reported physical activity was over-estimated compared to accelerometer data at follow-up with a very weak negative correlation  and did not experience breast cancer symptoms much (3.8 ± 2.8). Participants felt that their treatment could help their breast cancer (7.8 ± 2.3) and they felt that they understand their breast cancer well (8.1 ± 1.7). However, they felt they had moderate control over their breast cancer (5.0 ± 3.0), concerns about their breast cancer (5.7 ± 2.9) and reported that their breast cancer affected them emotionally (5.0 ± 3.0). When participants were asked what they thought caused their breast cancer (free-text), several common themes emerged: ‘stress’, ‘genetics/family history’, ‘not sure’, ‘bad luck/chance’, ‘age’, ‘oestrogen/hormones’ and ‘unhealthy lifestyle’ . Participants ranked the three most important causes of their breast cancer as (1) unhealthy lifestyle, (2) stress and (3) not sure.At follow-up, there were no significant differences between groups for participants’ illness perceptions across the 8 domains . She reported that ‘it’s nice to reply, so you get feedback’ (age 58). The most common replies were giving thanks, comments about personal health or complimenting EMPOWER-SMS (Box 1). One photo and 12 ‘reactions’  were received. Thirteen messages included an emoji; usually a smiley face or heart. The most common themes that triggered a reply were self-care or managing side effects , practical health tips , exercise  or diet .A total of 8061 text messages were sent; 7925/8061 (98.3%) delivered successfully and 136/8061 (1.7%) bounced. Despite being instructed not to reply, participants replied 130 times , useful  and motivated them to change their lifestyle . Half reported messages helped remind them to take their endocrine therapy medication . Most  participants thought that the six-month program length was just right and 10/64 (14%) it was too short or much too short. Most participants  saved the messages. However, only 28/64 (44%) shared them with family/friends and 7/64 (11%) forwarded the messages to others  EMPOWER-SMS participants completed the intervention feedback survey Table . The majfestyle 4/64; 67%.Accessible health education and support after breast cancer treatment remains a challenge in survivorship care , 30. DesIn terms of the primary outcome (self-efficacy), it is possible that the chosen scale (self-efficacy for managing chronic disease) was too broad to identify a change in this population. This scale combines self-rated self-efficacy across multiple domains including managing fatigue, pain, emotional distress and ‘things other than medications’. A previous study with cancer survivors found that self-efficacy can vary greatly across domains , indicatDespite the positive data relating to usefulness and motivation, it is also possible that text messages alone are insufficient to produce a change in self-efficacy for female breast cancer survivors. A systematic review with meta-analysis of healthy adults found that the effect of digital health interventions on self-efficacy decreased as the number of women included in the study increased . Moreovedoubled medication adherence compared to usual care [daily text message reminders, and some required a response (two-way communication) [The current study provided preliminary evidence that a lifestyle-focused text message intervention can improve endocrine therapy medication adherence compared to usual care. This result mirrors findings of increased medication adherence compared to control for patients with coronary heart disease , HIV posual care . Contrarication) –39. A syication) . Moreoveication) . Qualitaication) . To our ication)  and may This study’s results are confounded by the global COVID-19 pandemic. In March 2020, COVID-19 restrictions in Sydney Australia included a stay-at-home order, which mandated working from home and closure of non-essential services . For breAlthough the study had many strengths, including successfully testing a new co-designed digital health intervention in a high quality RCT with a population of culturally and ethnically diverse breast cancer survivors, several limitations should also be considered. Due to COVID-19 restrictions, half of the participants were followed-up by phone. Body composition data  were therefore unavailable and weight and waist-circumference measurements were self-reported, which limited power and accuracy . Also, pA semi-personalised lifestyle-focused text message intervention for women post-active breast cancer treatment was not associated with improvements in the primary (self-efficacy) or secondary outcomes but did have a small significant improvement on endocrine therapy medication adherence. Moreover, the program was deemed useful, acceptable, and motivating for behaviour change and medication adherence from a socioeconomically diverse population. The program provides a feasible, inexpensive, and easily scalable strategy for providing post-treatment health information and support remotely, including during COVID-19 lockdowns. The program could benefit from implementation closer to the end of active treatment and longer-term follow-up.ESM 1(DOC 91 kb)ESM 2(DOCX 20 kb)ESM 3(DOCX 20 kb)ESM 4(RTF 101 kb)


The aim of the study was to verify the knowledge on oral cancer and to assess possible differences in awareness and information basing on different demographic and subject-related factors. An anonymous survey was provided to 750 random subjects using online-based questionnaires. Statistical analysis was performed in order to evaluate the influence of demographic variables  on knowledge of oral cancer and its risk factors. 68.4% of individuals knew about the existence of oral cancer, mostly from media and family/friends. Awareness was significantly influenced by gender and higher education, but not by age. Most participants recognized smoking as a risk factor, but alcohol abuse and sunlight exposure are less known, especially among less educated subjects. On the contrary, our study shows a diffusion of false information: more than 30% of the participants indicated the possible role of amalgam fillings in oral cancer onset, independently of gender, age or education. The results of our study suggest the need for oral cancer awareness campaigns, where school and healthcare professionals should be actively involved in promoting, organizing and finding methods to monitor the medium and long-term efficacy with proper methodological quality. Oral squamous cell carcinoma (OSCC) represents one of the most common, yet scarcely known malignancies worldwide, affecting more than 300,000 individuals per year and causing 177,384 deaths annually, representing nearly 2% among all cancer sites . AlongsiIn accordance with other cancer types, the etiology of OSCC is strongly related to specific lifestyle habits and behavior, which include tobacco smoking, alcohol abuse, exposure to sunlight ultraviolet (UV) radiation, and human papilloma virus (HPV) infection . The latInformative campaigns about OSCC and other cancer types characteristics and risk factors are performed worldwide, but their efficacy in reducing the time occurred by symptoms onset and referral to a proper physician are difficult to evaluate . The risThe aim of our study was to verify the knowledge about different aspects of OSCC and to assess possible differences in awareness and information basing on different demographic and subject-related factors such as age, gender and education level.A questionnaire on OSCC knowledge was designed by the clinical staff of the Oral Medicine and Pathology Unit  and by the Scientific Promulgation Office (University of Trieste). Questions were developed basing on a previously employed questionnaire on OSCC knowledge among pre-adolescents and adolescents  and implThe face validity of the questionnaire including appropriateness, logical sequence and comprehensibility of the questions was examined by 10 subjects . The impact score (IS) of each item was calculated using a five-point Likert appropriateness scale ranging from 1  to 5 (highly appropriate) and items scoring <1,5 were removed from the questionnaire . SubsequThe questionnaire was distributed by students randomly to subjects with minimum age of 11 years visiting the University of Trieste stand during the “Trieste NEXT” 3-day long science dissemination event. Subjects were visitors of different ages randomly accessing a free-entrance pavilion set up in the context of a public dissemination initiative. Subjects were asked their consent to participate, and in case of acceptance were provided with a tablet to answer the items. A total of 750 questionnaires were completed. After the conclusion of the initiative, the data from the questionnaires were processed anonymously. Results were reported into a Microsoft Excel table and analyzed as frequency counts, percentages, and/or means.http://www.R-project.org/). Fishers’ exact test (for 2 × 2 contingency tables) was used to evaluate the association among different variables and OSCC awareness. All of the variables significantly associated with OSCC awareness were introduced into a multiple logistic regression model. Forward stepwise algorithms were used, with the rejection of those variables that did not fit the model significantly. Odds ratio (OR) and 95% confidence intervals (CIs) were also calculated. A p-value < 0.05 was used to reject the null hypothesis.Statistical analysis was performed using R software, version 4.0.2 , followed by general practitioner, oncologist and otolaryngologist. Only 4.6% of the subjects would turn on to a dermatologist.Almost all participants think that there is need for additional information about oral cancer (98.2%), mostly through school (76.5%), internet/social media (65.7%) and television (58.2%). In participants' opinion, the appropriate age to start addressing the topic of cancer and its prevention would be 15–18 years (56.1%), followed by 11–14 years (38.8%).p = 0.02) and education (Fisher's exact test p = 0.01), but not by age (Fisher's exact test p = NS). In particular, male subjects were less aware , while participants with higher levels of education  were significantly more informed.p < 0.05), with male subjects being less aware . Alcohol consumption was less frequently known in all subgroups, except for participants with higher education levels, whose knowledge was 1.65-fold higher than in participants with lower education levels (Fisher's exact test p < 0.001). The awareness of the correlation between sunlight exposure and OSCC was low in all subgroups without significant differences.Knowledge about cigarette smoking, as risk factor for OSCC development, was significantly affected by gender (Fisher's exact test p = 0.02), while older  and highly educated  participants were significantly better informed. However, there were not significant differences in knowledge about amalgam fillings not being associated with the risk of OSCC onset.A proportion of participants wrongly indicated fluoride or amalgam fillings as risk factors for OSCC development. In particular, male subjects were more likely to indicate fluoride as a risk factor  seem to foster knowledge and sensitization. This is an interesting result, as epidemiological data show that male gender has nearly double-fold incidence and mortality for OSCC with respect to female gender  and shouWe observed a higher level of awareness about the importance of early diagnosis in improving survival rates, and about the importance of changing lifestyle habits in order to reduce the risk of developing oral cancer. Interestingly, there is a different level of awareness about risk factors. Subjects correctly identified smoking as the major risk factor 94.1%), consistently with the data obtained in our previous campaign among preadolescents 92.2%), and in a higher proportion compared with studies performed in Italy  and in o%, consis.2%, and Alcohol abuse is the other major risk factor for OSCC development, but it is generally scarcely recognized both in our (51.3%) and in other previously published studies , 25, 32.Together with the scarce consciousness of ascertained risk factors, some media and uncontrolled information spreading often lead to consolidation of misbeliefs. The possible association between fluoride-based products and especially amalgam fillings with systemic diseases including malignancies, although not supported by scientific evidence, is unfortunately widespread. Our data confirm that both have been listed as potential risk factors for OSCC but to a different extent: while few subjects indicated fluoride (12.7%) without differences among subgroups, amalgam fillings were chosen by nearly one third of the participants (34.7%). Both proportions are higher than the ones obtained in our previous study conducted among preadolescents . In partin primis, followed by internet, social media and television. The appropriate age to start addressing cancer prevention issues, in our population's opinion, would be above 15 years. However, even preadolescents are already exposed to large amount of information about healthcare topics including cancer, possibly leading to misunderstandings and misbeliefs, being the reliability of the sources often difficult to understand. In our experience, such dissemination events and campaigns are fully understood and appreciated even in subjects aged 11–14 . Although interesting data have emerged , further deepening and cause/effect relationships were not possible because specific questions were not included in the questionnaire.Social campaigns designed to raise awareness about the risk factors of different cancer types remain a widespread method to improve their prevention and/or promote early diagnosis . HoweverTaking into account the geographical and numerical limitations, the results of our study suggest how there is definitely the need for oral cancer awareness campaigns, where school and healthcare professionals (in this case dentists), appropriately trained and informed, should be actively involved in promoting, organizing and finding methods to monitor the medium and long-term efficacy of cancer prevention dissemination campaigns, with proper methodological quality. The possible interventions may include direct contact, mass media, small media or group education initiatives and further studies are needed to compare their effectiveness.


Given the role of insulin resistance in several cancers, we hypothesized that consumption of a diet that reduces insulin resistance might lower the risk of breast cancer.The present study was designed to assess the association between consumption of “diabetes risk reduction diet” (DRRD) and odds of breast cancer among a large group of women in a Middle Eastern country.via a validated 106-item Willett-format semi-quantitative dish-based food frequency questionnaire. A DRRD score was included based on 9 dietary factors . For food and nutrient items with a protective association with diabetes in earlier studies, participants were given the score as the quintile of that food item, but for food groups with unfavorable association with diabetes, we did vice versa. Total DRRD score ranged from 5 to 45.This population-based case-control study enrolled 350 newly diagnosed cases of stage I-IV breast cancer and 700 age-matched apparently healthy individuals as controls. We collected dietary data P-trend = 0.002). Stratified analysis by menopausal status indicated a significant inverse relationship in postmenopausal women , but not in premenopausal women . Moreover, by BMI status, we found statistically significant inverse association between adherence to the DRRD and odds of breast cancer among normal-weight women  but not in overweight women . Conclusions: Significant inverse associations were found between adherence to DRRD and breast cancer, especially among postmenopausal and normal-weight women.Mean age of cases and controls was 65.28 and 61.04 years. Mean BMI of patients with breast cancer and controls was 25.5 and 21.0. We found that individuals with the greatest adherence to the DRRD were 0.41 times less likely to have breast cancer than those with the lowest adherence (OR: 0.59; 95% CI: 0.38, 0.90, and  The prevalence of breast cancer and mortality due to cancer is higher in patients with diabetes than in healthy individuals , 2. A meIn terms of dietary factors, construction of a dietary pattern including high glycemic index –14, refiTo date, no study has examined DRRD score with risk of breast cancer in the Middle Eastern population, where the risk of diabetes and breast cancer is increasing and the traditional dietary pattern is different from current typical diets in Western countries . ConsumpThis case-control study was performed on women over 30 years of age between 2013 and 2015 in Isfahan, Iran. We recruited cases from patients who were referred to private hospitals or clinics or were being treated for breast cancer, including tumor resection, chemotherapy, or radiotherapy, or all of them. Breast cancer was pathologically confirmed in cases who had been diagnosed with this condition in the past 6 months through physical examination and mammographic findings. Given that patients were only asked to answer some of the questionnaires, more than 90% of them accepted to take part in the study. The sample size was calculated considering the type I error as 5% and the study power as 80%. In addition, we hypothesized that unhealthy dietary pattern might increase the odds of breast cancer by 1.5 times. Considering the common ratio of 0.25 and the ratio of controls to cases as 2, we needed ~350 patients with breast cancer and 700 apparently healthy controls. In this study, we did not include people with a history of any neoplastic lesions or cysts (except breast cancer) and those who had previously been treated with any hormone replacement therapy. In addition, we did not include people on a special diet in the project. The control group was consisted of Iranian women who had no history of malignancy, cysts, or pathological disease and had no specific diet or hormone replacement therapy. Healthy women in the control group were matched with cases in terms of age and socioeconomic status. Individuals in the control group were chosen from healthy women with no family history of breast cancer by multi-stage cluster random sampling. Finally, a total of 1,050 eligible women, including 350 cases and 700 controls, were recruited to participate in our study. All participants provided informed written consent. The study was ethically approved by the Bioethics Committee of Tehran University of Medical Sciences, Tehran, Iran.We collected usual dietary intakes of subjects using a 106-item Willett-format semiquantitative dish-based food frequency questionnaire (FFQ), which was designed specifically for Iranian adults. Details of developing this questionnaire as well as further information about its validity and reliability were reported elsewhere . All theBased on earlier knowledge about the association between various food items and diabetes, DRRDS was constructed using previously published reports. Nine food items including cereal fiber, nuts, caffeine, whole fruits, ratio of polyunsaturated fat to saturated fat, GI, trans fats, SSBs/fruit juices, and red and processed meats were considered in this scoring method. First, we classified participants in terms of quintiles of these components. For food and nutrient items with a protective association with diabetes in earlier studies , participants were given the score as the quintile of that food item; that is individuals in the highest quintile of these foods and nutrients were given the score of 5 and those in quintiles 1, 2, 3, and 4 were given the scores of 1, 2, 3, and 4, respectively. For nutrients and food groups  with unfavorable association with diabetes, we did vice versa; such that individuals in the highest quintile were given the score of 1 and those in the lowest quintile received the score of 5. Similarly, individuals in quintiles 2, 3, and 4 were given the scores of 4, 3, and 2, respectively. Total DRRDS was computed by summing up the scores of participants received for all nine components. This score ranged from 5 to 45 .The diagnosis of breast cancer was done using physical examination and mammography. Pathological evaluation was also performed to confirm the diagnosis. We included women of Iranian nationality who had been diagnosed with breast cancer for the maximum of previous 6 months and also had stage I–IV breast cancer.via pretested questionnaires. In order to assess the level of physical activity, the short form of the International Physical Activity Questionnaire (IPAQ) was used, in which the metabolic equivalents-hour per week (MET-h/week) was computed to state the activity level for each study participant , past medical history, family history of breast cancer, history of breastfeeding and dietary supplement use dietary supplements  were collected ticipant . Weight post-hoc comparison for pairwise differences. To examine the relationship between DRRD adherence and breast cancer, multivariate logistic regression was used in several models for all participants. The obtained findings were modified for confounding factors including age, residence, marital, menopausal and socioeconomic status, education, family history of Breast cancer, breast feeding, history of disease, and dietary supplement use. Further adjustment for BMI was applied in the last model. Stratified analyses by menopausal status as well as BMI were also conducted. We used quartile categories as an ordinal variable, in order to assess the trend of odds ratios across increasing quartiles of DRRD score. All analyses were done via Statistical Package for Social Sciences . P < 0.05 were identified as statistically significant.We categorized participants into quartiles according to DRRD adherence. In order to compare general characteristics of study population across quartiles DRRD adherence, one-way ANOVA for continuous variables and Chi-square test for categorical variables were applied. Dietary intakes of study participants across categories DRRD adherence were evaluate by ANOVA, with Tukey's 2 was 271 (77.4%) among cases and 352 (50.2%) among controls. Also, the participants with BMI ≥ 25 kg /m2 were 79 (22.5%) in the cases and 348 (49.7%) in the control group. General characteristics of the study population across quartiles of DRRDS are presented in P < 0.01 for all). Moreover, a lower percentage of them were residing in urban areas. No other significant differences were found across categories of DRRDS in terms of other general characteristics.A total of 1,050 female participants with a mean age of 62.5 years were included in the study. Number (percentage) of individuals with BMI < 25 kg/mP < 0.001). The Tukey's post-hoc analysis was performed to compare pairwise differences between dietary intakes of study participants across quartile categories of DRRDS in P < 0.001 for all). In contrast, the consumption of fat (P: 0.012), trans fatty acids (P < 0.001), and red and processed meats (P < 0.049) of participants in the third category was lower than that of the first category. Also, individuals in the top quartile of DRRD had higher energy (P: 0.001), carbohydrate (P < 0.001), protein (P < 0.001), fiber (P < 0.001), cereal fiber (P < 0.001), nuts (P: 0.003), caffeine (P < 0.001), whole fruits (P: 0.012), higher PUFA to SFA ratios (P: 0.010), and GI (P: 0.006), than participants in the lowest quartile. In addition, those with the highest quartile had lower intakes of fat (P < 0.001), trans fatty acids (P < 0.001), SSBs / fruit juices (P: 0.002), and red and processed meats (P < 0.001), vs. those with the lowest quartile.Dietary intakes of the study population across quartiles of DRRDS are displayed in P-trend < 0.001). Further adjustment for BMI did not change the mentioned association . When we did the analysis stratified by menopausal status, we found that postmenopausal women with the highest DRRDS score had 37% lower odds for having breast cancer compared with those with the lowest score . This inverse association remained significant after adjustment for several potential confounding variables , even BMI . However, no significant association was seen between DRRDS and odds of breast cancer in premenopausal women, either before  or after adjusting for potential covariates .Crude and multivariable-adjusted ORs and 95% confidence intervals (CIs) for breast cancer across categories of DRRDS score are outlined in P-trend = 0.006) or after controlling for potential confounders . No significant associations were seen between DRRDS and odds of breast cancer in obese women, comparing top vs. bottom quartiles . Adjustment for potential confounders did not affect the findings .We repeated the regression analysis according to BMI status , in whicTo the best of our knowledge, the current study is the first in the Middle East to investigate the association between DRRDS and odds of breast cancer. In this case-control study among 1,050 Iranian women, we found a significant inverse association between DRRDS and odds of breast cancer. This inverse association was also observed in postmenopausal women, either before or after controlling for confounders. Separately by BMI status, this inverse relationship was seen among normal weight women, but not in overweight or obese people.Breast cancer is a growing public health concern worldwide . Along wn = 199) may explain lack of a significant relationship between DRRDS and the odds of breast cancer, but it must be kept in mind that such an association was not also seen in a previous cohort study with a large sample size of premenopausal women  are the most important negative regulators of the sex hormone-binding globulin (SHBG) synthesis pathway  of ways , 68. In  of ways , 69. The of ways , 69. DRR of ways –73. ThusThe present study contains several strengths. This is the first study in the Middle East to examine the association between DRRDS and breast cancer. Adequate number of studied people, accurate assessment of potential confounders and controlling for them in the analysis are also among the strengths of the present study. Another strength of this study was that the food questionnaires were completed in a face-to-face interview by a trained nutritionist. The use of the USDA food composition table, which was modified for Iranian local foods using the nutrient composition of Iranian food items, was another strength of this study. The limitations of the study include the following points: (1) the study type is case-control which would prevent the inference of causation and (2) this study is subject to selection and recall bias. However, applying the population-based study, we tried to reduce the possibility of selection bias, (3) measurement errors are unavoidable and would lead to misclassification of participants, (4) proportion of postmenopausal women was higher than premenopausal, which might explain finding the expected association in this group only, (5) failure to assess insulin resistance, and (6) lack of data on the hormonal status of breast cancer and medication use in this people are another limitation.Overall, we found that consumption of “diabetes risk reduction” diet was associated with a reduced odds of breast cancer, in particular among normal-weight women and postmenopausal women. Additional studies in other countries of the Middle East are needed to further examine this hypothesis in the region.The raw data supporting the conclusions of this article will be made available by the authors, on reasonable request to the corresponding author.The studies involving human participants were reviewed and approved by Ethical Committee of Tehran University of Medical Sciences approved the study protocol. The patients/participants provided their written informed consent to participate in this study.LA and SB-K contributed to data collection, assisted in designing the study, conceptualized, and oversaw this study. AB and AE provided substantial contributions to the editing of the paper. SE took primary responsibility for drafting this manuscript. AB and SE provided guidance on the analysis. AE conducted the analysis. All authors contributed to the article and approved the submitted version.The financial support for this study comes from Tehran University of Medical Sciences, Tehran, Iran.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The most prominent form of cancer in women is breast cancer, and modifiable lifestyle risk factors, including smoking, alcohol consumption, and induced abortion, can all contribute significantly to this disease.  This study's primary purpose was to assess the prevalence of breast cancer among women in developed and developing countries and the association between three modifiable hazard factors  and breast cancer.  This study performed a systematic literature database review up to September 21, 2021. We employed meta-analytic tools such as the random effects model, forest plot, and subgroup analysis to conduct the research. Additionally, we conducted a sensitivity analysis to assess the influence of outliers.  According to the random effects model, smoker women have a higher risk of developing breast cancer from different countries . In the case of induced abortion, the pooled estimate  indicated a significant link between abortion and breast cancer. Subgroup analysis revealed that smoking substantially influences breast cancer in developing and developed countries. Breast cancer was more common among women who smoked in developed countries than in developing nations.  The observed findings give sufficient support for the hypothesis that smoking and abortion have a significant influence on breast cancer in different nations. Health organizations should individually design comprehensive scientific plans to raise awareness about the risks of abortion and smoking in developed and developing countries. As the most commonly diagnosed neoplasm, breast cancer is a leading cause of cancer-related mortality among females in both developed and less developed nations , 2. CancThe previous works of literature were individually searched in four English databases  and most commonly searched in Google Scholar. These searches are conducted manually. The searching strategy utilized different search keywords in each database: (1) “breast cancer,” “breast carcinoma,” “breast tumor,” “breast neoplasm,” “mammary cancer,” “mammary carcinoma,” “mammary neoplasm,” “smoking,” “alcohol consumption,” and “abortion.” (2) “Breast cancer,” “smoking,” “alcohol consumption,” and “abortion.” (3) “Risk,” “risk factors,” “influencing factors,” “susceptibility,” phrased with “breast cancer,” “smoking,” “alcohol consumption,” and “abortion.” (see supplementary We considered literature in the present investigation based on the following criteria: (a) bivariate data available for the breast cancer risk with alcohol consumption, smoking influence, and abortion cases; (b) article full-text availability; (c) information made available in the English language; and (d) peer-reviewed, accepted, or published articles. The authors evaluated the appropriateness of the studies after finding the full texts. In the case of multiple studies in one country, the data of individual variables were appropriately merged.  Population: women with breast cancer.  Intervention: consider three lifestyle-related indicators  of developing breast cancer.  Comparison: consider three lifestyle-related indicators  of developing breast cancer.  Outcomes: breast cancer, mammary neoplasm, breast neoplasm, breast tumor, mammary cancer, breast carcinoma, and mammary carcinoma.  Study design: prospective study, cross-sectional study, cohort study, and case-control study.The following criteria for including different studies were identified in accordance with the PICOs acronym:Initially, 895 articles were appended after employing distinct search strategies and PICOs schema for each database. In the final stage, the authors rechecked and rescanned the abstracts of the included papers to ensure their accuracy. p values and I2 of the datasets [I2, and the value ranges from 0 to 100% [p values of 0.05 indicating the occurrence of publication bias [We have applied the software R version 3.6.2  and IBM SPSS version 27  to convey the investigation. We utilized meta-analysis to examine studies from different countries. Computing values evaluated heterogeneity using the datasets , 43. We datasets . The Q s to 100%  to displ to 100% . A leave to 100% . We util to 100% . For theion bias .p values of 0.05 indicating the occurrence of publication bias. We also considered the impacting factors of alcohol consumption, smoking, and abortion cases included as covariates to execute the exploration and find out the most impacting factors around the world.In this meta-analysis, we well-thought-out breast cancer as the dependent variable. In addition, Egger's test was used to estimate the risk of publication bias, with I2, we have come to know that 95.2% of the overall variation is due to true heterogeneity (which can be explained). Also, the observed weighted value of S.S. is 456.00 with df = 22 and p value <0.001, thus significant.I2, we have come to know that 98.8% of the overall variation is due to true heterogeneity (which can be explained). Also, the observed weighted value of S.S. is 1930.79 with df = 24 and p value <0.001, which is significant.I2, we have come to know that 84.7% of the overall variation is due to true heterogeneity (which can be explained). Also, the observed weighted value of S.S. is 117.96 with df = 18 and p value <0.001, which is also significant.p < 0.01, I2 = 90%) compared to women in developed countries  than in women who smoked in developing countries  and 0.0884 (abortion). It implies that there is no asymmetry in the funnel plot, which is compatible with the absence of publication bias. Therefore, the funnel plots depicted in Figures At the 5% level of significance, Egger's test for a regression intercept produced nonsignificant The purpose of this study is to systematically identify the degree of association between three lifestyle-related indicators  and breast cancer risk in women in developed and least developed countries. Based on a systematic review of observational studies published in 2020 in PubMed, Wiley, and ScienceDirect, the study was analyzed. According to the author's best knowledge, this is one of the first studies to execute a meta-analysis of tracking breast cancer risk using three lifestyle-related indicators. The random effects model in the meta-analysis found that exposure to smoking and abortion was significantly related to the chance of developing breast cancer.Women who smoked had a 45 percent greater likelihood of having breast cancer than women who did not smoke. Smoking appears to raise the chance of developing breast cancer in both developed and developing countries. The positive relationship between smoking and breast cancer that was discovered in the present studies was consistent with previous research –53. The Individuals with a history of abortion were also found to have an increased chance of developing breast cancer. A meta-analysis reached a similar conclusion, indicating that abortion increases women's risk of breast cancer . EarlierIn keeping with the findings of past systematic reviews, this investigation found no statistically significant relationship between alcohol use and breast cancer risk , 61. TheThis current study also includes a subgroup analysis to demonstrate the effects of abortion and smoking on breast cancer in developing and developed countries. The risk of breast cancer is greater across developing territories because of abortion than in developed countries, consistent with an earlier study . The nonSmoking and abortion are two risk factors for breast cancer among women in developed and least developed countries, as shown in the present study. Strengthening the implementation of MPOWER policies might help create awareness among women about the hazards of smoking. In addition, multifaceted interventions like government, nongovernment, and NGO's health programs based on sexuality education, unintended pregnancy awareness, and effective contraception and emergency contraception are needed to reduce abortion in society, thus controlling the risk of breast cancer. Besides, comprehensive science-based strategies for developed and developing countries might be designed individually to create awareness about the risks of abortion and smoking.Thus, smoking and induced abortion are connected with breast cancer in different nations, which has clinical significance. Its explication will aid health organizations and stakeholders in establishing comprehensive scientific plans to promote awareness about the risks of abortion and smoking in women. This agreement is supported by the extant literature , 70. A sThere are numerous unique strengths in the present study. Firstly, the methodology is the main advantage, as the systematic reviews combine findings from several published studies and draw a pooled conclusion from them. Secondly, this study considered three exposures to identify their relationship with breast cancer risk. Thirdly, subgroup analysis appends an additional advanced dimension to the current study.The current study is not without limitations. Firstly, the methodology follows observational trials that restrict the nature of the generalizability of the study findings . SecondlInitially, the risk of breast cancer was not associated with smoking-related cancer. Over time, however, sufficient evidence has accumulated to suggest that smoking is correlated with an increased risk of breast cancer. Although this study found no correlation between drinking and breast cancer, it did find a substantial association between induced abortion and breast cancer. This study reveals that the risk of breast cancer linked to smoking is higher in developed nations than in developing countries. So, the authority should consider these influences and make their strategies to raise awareness accordingly among people to reduce the smoking habit for a better healthcare situation in their respective countries.


MTHFR gene could influence homocysteine, methionine, and S-adenosylmethionine levels and, indirectly, nucleotide levels. Imbalance in methionine and S-adenosylmethionine synthesis affects protein synthesis and methylation. These changes, which affect gene expression, may ultimately promote the development of breast cancer. We therefore hypothesized that such mutations could also play an important role in the occurrence and pathogenesis of breast cancer in a Malian population. In this study, we used the PCR-RFLP technique to identify the different genotypic profiles of the C677T MTHFR polymorphism in 127 breast cancer women and 160 healthy controls. The genotypic distribution of the C677T polymorphism in breast cancer cases was 88.2% for CC, 11.0% for CT, and 0.8% for TT. Healthy controls showed a similar distribution with 90.6% for CC, 8.8% for CT, and 0.6% for TT. We found no statistical association between the C677T polymorphism and breast cancer risk for the codominant models CT and TT (p > 0.05). The same trend was observed when the analysis was extended to other genetic models, including dominant (p = 0.50), recessive (p = 0.87), and additive (p = 0.50) models. The C677T polymorphism of MTHFR gene did not influence the risk of breast cancer in the Malian samples.Methylenetetrahydrofolate reductase (MTHFR) plays a major role in the metabolism of folates and homocysteine, which in turn can affect gene expression and ultimately promote the development of breast cancer. Thus, mutations in the  MTHFR) gene. MTHFR, known as an essential enzyme in folate metabolism, is involved in the regulation and conversion of homocysteine to methionine [MTHFR catalyzes the irreversible reduction of 5,10-methylenetetrahydrofolate  to 5-methyl-THF. The major circulating form of folate, 5-methyl-THF, serves as a substrate for the methylation of homocysteine to methionine by using methionine synthase, which has vitamin B12 as a cofactor. Methionine enables the de novo biosynthesis of S-adenosylmethionine (SAM), which is the main donor of methyl radicals in humans [MTHFR gene, including the substitution of a cytosine at position 677 by a thymine (C677T) [MTHFR, is implicated in the processes of hypermethylation and hypomethylation of DNA [Breast cancer is a major public health problem in both developed and developing countries –3. Accorthionine . Indeed,n humans , 8. Many (C677T) , 10. The (C677T) –15. It hn of DNA  and couln of DNA , 15, 17.C677T in modulating the risk of cancer remain controversial. Several meta-analyses and reviews indicated that the C677T variant was associated with a risk of breast cancer [C677T polymorphism on DNA methylation, we hypothesize that this polymorphism could play a major role in the pathogenesis of breast cancer in Mali, a multiethnic, West African population. To the best of our knowledge, data on the relationship between the C677T variant of MTHFR gene and the risk of breast cancer are lacking for the Malian population. In this study, we assess the association between the C677T polymorphism of MTHFR and breast cancer risk in a sample of Malian women with breast cancer and health controls.Data in the literature about the role of t cancer , 18, 19.t cancer , 21. GivStudy participants with breast cancer, who were seeking care at the oncology and pathology departments of University Hospital Center of Point G, Bamako, between July 2018 and January 2020, were recruited. Health controls were recruited at the Center National de Transfusion Sanguine (CNTS) in Bamako, Mali, which facilitated the recruitment of age-matched controls to patients. Age at diagnosis, tumor location, use of contraception, menopausal status, parity, breastfeeding, family history of breast cancer, history of benign breast disease, obesity, smoking, histological type, tumor size, lymph node involvement, and metastases, were manually extracted from each patient's operative record. Inclusion criteria of study participants with breast cancer were women of age 18–55 years with confirmed breast cancer, availability of demographic, clinical and histological information, and absence of other cancer(s) and/or chronic disease(s). Inclusion criteria for healthy control participants were women of age 18 to 55 years without any history of malignancy or chronic disease. The study was approved by the Ethics Committee of the Faculty of Medicine and Odontostomatology/Faculty of Pharmacy (2018/63/CE/FMPOS) at the University of Sciences, Techniques, and Technologies of Bamako (USTTB), and all participants provided informed consent before any study activities.C677T polymorphism of MTHFR, using the forward and reverse primers sequences, as described previously [μl final reaction volume containing 10 X reaction buffer, 25 mM MgCl2, 5 mM dNTP, 5 μM primers, 500 U of Taq DNA polymerase, and 100 ng genomic DNA was used to amplify C677T from MTHFR. PCR amplification conditions included an initial denaturation step for 5 minutes (min) at 95°C, followed by 35 cycles: denaturation at 95°C for 1 min, annealing at 55°C for 1 min with extension at 72°C for 1 min. A final extension step was carried out at 72°C for 7 min. The PCR products were electrophoresed on 2% agarose gels stained with ethidium bromide. The C to T substitution at position 677 of MTHFR creates a restriction site with HinfI enzyme for the C677T MTHFR polymorphism. After amplification and digestion, PCR products showed one fragment of 198 bp for wild CC, three fragments of 198, 175, and 23 bp for CT and two fragments of 175 and 23 bp for TT , using GentaPuregene Extraction Kit, Qiagen. Spectrophotometer was used to check the quantity and quality of the DNA. The PCR-RFLP technique was used to determine the eviously . A 25 μlp for TT . In addiC677T polymorphism of MTHFR and demographic, clinical, and histological characteristics was assessed using the χ2 test. The same test was used to check Hardy−Weinberg equilibrium. The association between the C677T polymorphism and the risk of breast cancer in all genetic models (codominant: CT versus (vs.) CC and TT vs. CC, dominant: CT + TT vs. CC, recessive: TT vs CT + CC, additive: T vs C) was measured by calculating the OR with 95% confidence interval (CI). A p value less than 0.05 was considered significant in all tests.SPSS 16.0 software  was used for statistical analysis. The relationship between the C677T polymorphism of MTHFR and clinicopathological characteristics in breast cancer patients (p > 0.05)  and 6 cases with other histological forms  and 160 healthy controls. The mean age of patients was 43.30 ± 2.1 years and 41.2 ± 2.5 years for control subjects, respectively.  > 0.05) .C677T MTHFR polymorphism the in breast cancer group according to genetic models. The distribution of genotypes was 88.2% for CC wild type, 11.0% for CT heterozygous, and 0.8% for TT mutant homozygous in the cases and 90.6% for CC, 8.8% for CT, and 0.6% for TT in the controls. The allelic frequencies in cases and controls were 93.7% for C, 6.3% for T, and 95.0% for C, 5.0% for T, respectively. None of the genetic models showed a significant association of the C677T polymorphism and risk of breast cancer, including the codominant model , dominant model , recessive model , and additive model   and controls . = 0.50) . The disT allele in our healthy controls (5.0%) was statistically comparable to those reported in West African countries, including, Burkina Faso (6.0%) [T allele in healthy women appears to depend on the study population and ethnic origins.We observed that the frequency of the mutant o (6.0%) , Nigeriao (6.0%) , Gambia o (6.0%) , Togo (8o (6.0%) , and Ghao (6.0%) . In conto (6.0%) , Moroccoo (6.0%) , Iran (2o (6.0%) , Turkey o (6.0%) , Brazil o (6.0%) , United o (6.0%) , Italy (o (6.0%) , China (o (6.0%) , and Mexo (6.0%) . The widC677T polymorphism of MTHFR is not linked with the occurrence of breast cancer in a sample of women from Mali. Numerous studies have been undertaken to assess the influence of the C677T polymorphism of MTHFR in breast cancer, but the conclusions remain conflicted. Our results are consistent with previously published work, which found no significant association with risk of breast cancer [C677T polymorphism of MTHFR and risk of breast cancer in Caucasian women, but not in Asian women [C677T polymorphism with the risk of breast cancer in Latino women [C677T polymorphism of MTHFR with occurrence of breast cancer could be due to sample size, ethnic origins, genetic background, linkage disequilibrium, and in particular the lifestyle of the populations studied.The present case-control study revealed that the t cancer , 31, 33.an women , 20, 34 no women . The disMTHFR mutation promotes the development of breast cancer has not yet been fully established, the C677T polymorphism has been considered to be a variant producing a thermolabile enzyme with limited activity. This variant is the most common genetic cause of hyperhomocysteinemia [MTHFR) catalyzes the irreversible reduction of 5,10-methylene tetrahydrofolate (CH2THF) to 5-methyltetrahydrofolate (CH3THF) [MTHFR affects the availability of CH2THF, which influences the synthesis of RNA and DNA. MTHFR plays a major role in folate and homocysteine metabolisms by acting on the transfer of its methyl group during the remethylation of homocysteine by methionine synthase. MTHFR can modulate the levels of homocysteine, methionine, and S-adenosylmethionine and indirectly influence the levels of nucleotide, since its substrate, 5,10-methylene tetrahydrofolate, is used for the synthesis of thymidine [MTHFR deficiency can promote the development of oncogenic processes [MTHFR deficiencies. There is still a great deal of controversy about the role of MTHFR polymorphisms. However, a link with cardiovascular disease has been established, which may then have an indirect link with risk of breast cancer [C677T polymorphism of the MTHFR gene has been reported to be associated with an increased level of homocysteine, which may independently contribute to the development of stroke and coronary disease. The impact of the C677T polymorphism on the risk of developing of cardiovascular diseases, such as stroke (hemorrhagic or ischemic), venous thrombosis, and coronary heart disease has been reported in the Caucasian and Asian populations [Although a clear mechanism by which the teinemia , 37. In (CH3THF) . Thus, thymidine . The imbrocesses , 40. Thet cancer . The C67ulations –44. ThesThis study has some limitations. First, the sample size is relatively small; therefore, the results cannot be generalized to the entire Malian population. Second, hormone receptor tests  and blood folate levels could not be performed in the majority of patients. Determination of hormonal status enables better patient management while improving the prognosis. In addition, low blood folate levels may cause certain abnormalities such as cardiovascular and cancer diseases.C677T polymorphism of the MTHFR gene and risk of breast cancer. The distribution of the mutant T allele was very rare in both groups of women with and without breast cancer. Further studies with a folic acid assay should be performed to evaluate the association of the C677T MTHFR polymorphism and risk of breast cancer.In conclusion, this study did not show any association between the


Major depression disorder (MDD) has been associated with increased breast cancer risk in epidemiological studies; however, it is still unknown whether this association is causal or not. The aim of this study is to determine the causal relationship between MDD and breast cancer risk.Two‐sample Mendelian randomization (MR) analyses with 92 single‐nucleotide polymorphisms (SNPs) significantly associated with MDD as instrumental variables (IVs) were performed. Effects of these SNPs on breast cancer in women were estimated in the Breast Cancer Association Consortium  using inverse variance weighted (IVW), weighted median and multivariable MR models. Heterogeneity and pleiotropy effects were assessed based on IVW and MR‐Egger regression model, respectively.OR) = 1.087; 95% confidence interval (CI) 1.011–1.170; P = 0.025] per log‐odds ratio increment of MDD risk based on the IVW model was noticed. Similar results were obtained with the multivariable MR model . An increment but not statistically significant causality association was noticed between MDD and risk of ER+  or ER‐  breast cancer under multivariable MR model. No significant pleiotropy effects were observed for the IVs in the two‐sample MR studies.An 8.7% increased risk of overall breast cancer [odds ratio (The results suggested that a genetic predisposition of MDD is causally associated with overall breast cancer risk; however, the underlying biological mechanisms are worthy of further study. Using the two‐sample Medenlian Randomization analysis methods, we found a causal association between major depression disorder and breast cancer risk in women Consents from the participants were assumed to be obtained by the individual GWAS.2.1We applied the two‐sample MR study based on the public summary‐level data derived from the GWASs to evaluated the causal association between MDD and breast cancer risk. Genetic IVs were derived from the GWAS performed by Howard et al.,2.2P < 5 × 10−8), and the base pair positions of them were identified by clumping all associated variants across a 3 Mb window on chromosome (linkage disequilibrium r2 < 0.1) and have merged any overlapping clumps, indicating these IVs met the assumptions 1 and 2 of the two‐sample MR study design. Of them, four SNPs including rs78337797, rs56314503, rs10774600, and rs3213572 were not identified in the BCAC GWAS summary‐level data for breast cancer risk or with high LD proxy SNPs (r2 > 0.80). Another six SNPs including rs12052908, rs1933802, rs2029865, rs2247523, rs263645, and rs2876520 were discarded for being palindromic with intermediate allele frequencies , where EAF is the effect allele frequency, β is the estimated genetic effect on MDD. We calculated the F‐statistic to assess the strength of each IVs using the formulation: F = (R2 × [n − 1 ‐ k])/([1 ‐ R2] × k) as reported,R2 was calculated as proportion of variance in the phenotype explained by genetic variants, k is the number of IVs, and n is the sample size. An F‐statistic >10 has been recognized as a robust IV and recommended to be used in MR study.F‐statistic value of these genetic IVs ranged from 147 to 532 indicating sufficient strength of the IVs in the two‐sample MR studies  the IVs should be significantly associated with MDD risk; (2) the IVs should not be associated with other potential confounding factors; (3) there is no direct association between the IVs and breast cancer, or through any other way except the exposure (MDD) to correlate with breast cancer  using the TwoSampleMR package (version 0.5.6) of R (www.r‐project.org).r2 > 0.80) with validated IVs as determined using the 1000 genomes reference panel in European ancestry individuls. None of the IVs is significantly associated with breast cancer at the genome‐wide significance  GWAS database (2.4P < 5 × 10−8) with smoking initiation ,n = 335,394, GSCAN),n = 397,751, MRC‐IEU UK Biobank),n = 182,416, ReproGen) through querying the the IEU GWAS database (https://gwas.mrcieu.ac.uk) using the TwoSampleMR package.r2 > 0.001 in a 10,000 kb window of genomic region as final IVs.To account for the confounders including smoking, alcohol, age at menarche, education attainment, and incoming in MVMR study, we extracted SNPs that significantly associated  per log‐odds ratio increase with MDD in women. In the stratification analysis, we noticed the statistical power was 0.46 and 0.55 when the expected OR was 1.059 and 1.101 for ER+  and ER‐  breast cancer per log‐odds ratio increase with MDD in women, respectively. Statistical power estimates for the 92 genome‐wide significant SNP instruments by breast cancer subtypes are presented in Table The pos hoc statistical power was calculated using an online tool at 2.6R2 LD <0.1 based on the 1000 Genome panel reference) were included in the models (Table P < 0.05), and the effect estimates were recalculated after remove these outliers.P < 0.05.P values below 0.017 (where α = 0.05/3 breast cancer outcomes) were considered strong evidence of associations and P values between 0.017 and 0.05 as suggestive evidence of associations.In order to determine the causal relationship between MDD and breast cancer risk, we used the conventional inverse variance weighted (IVW) method, fixed‐effects IVW model, as well as the weighted median method to generate the main MR estimates. To account for the potential confounders in assessing MDD and breast cancer risk by the genetic IVs, we also performed the MVMR analysis adjusting for smoking, alcohol intake, education atttainment, income, and age at menarche. The genome‐wide significant signals of these exposures assessed independent of MDD‐related variants  for multiple testings. The leave‐one‐out analyses identified no individual IV largely affect the causal magnitude between MDD and the risks of total breast cancer under the IVW model .Based on the IVW model of two‐sample MR studies, we found that women were associated with an 8.7% increased risk of overall breast cancer . When we applied the MR‐PRESSO analysis, a stronger association was observed between the MDD and breast cancer risk after excluding potential outlying pleiotropic IVs , which reached the multiple testing significance threshold (P = 0.016). Further, the results from the MV analyses adjusting for potential confounders including regulatory smoking, alcoholic drinks per week, education attainment, household income (before tax), and age at menarche also suggested that MDD is associated with increased breast cancer .According to MR‐Egger test, there was no significant pleiotropy effects of the genetic IVs , weighted median methods and MR‐PRESSO corrected testing (Table P‐heterogeneity <0.001) and no significant pleiotropy effects of the IVs in assessing causality association between MDD and ER+ breast cancer risk were noticed. The leave‐one‐out analyses identified no individual IV largely affect the causal relationship between MDD and ER+ breast cancer under the IVW model .To further explore the causal relationships between MDD and the risks of breast cancer of different pathological subtype, we performed the two‐sample MR studies based on the summary level data form the GWASs performed in ER+ and ER‐ breast cancer patients. No statistically significant association was observed between MDD and ER+ breast cancer as suggested by the IVW methods , weighted median , and MR‐PRESSO analyses  and no evidence for the directional horizontal pleiotropy was identified in the MR‐Egger regression analysis .For ER‐ breast cancer, we noticed a statistically marginal causality relationship with MDD as suggested by IVW . MR study performed by Howard et al.An important assumption of MR is that the genetic IVs should not influence the outcome through a different biological pathway from the exposure of tested. Previous epidemiology studies suggested that MDD may lead to higher rates of smoking and alcohol intake.There were several advantages for the current two‐sample MR studies, first, because alleles follow the principle of random distribution when forming gametes during meiosis, the causal relationship between genotype and disease in MR studies will not be distorted by confounding factors, which is the main limitation of traditional observation studies. Second, it is much easier to use aggregated level data of public GWAS genetic consortia data to assess the causality relationships between MDD and breast cancer risk rather than the prospective cohorts studies or RCTs. The two‐sample MR study performed here required less time and expenses compare with common epidemiological studies. However, several limitations in the current studies need to be acknowledged in current study. First, the genetic IVs used in MR analysis are usually weak instruments, and only a small proportion of exposure variance was identified by the genetic IVs. The non‐causal connection between MDD and breast cancer in the stratification studies may be due to the low statistical power. Second, other confounding factors (such as population stratification and exposure time) may also affect the results. Third, because this study relies on aggregated GWAS data from people of European descent, the promotion of this result should be validated in other races.In conclusion, the current MR analysis showed that MDD was causally associated with the increase of overall breast cancer. This result support the view that early intervention should be conducted on the women with MDD to reduce the risk of breast cancer; however, the results need to be confirmed using other study designs, including prospective cohort studies and large‐scale intervention trials.QR, FL, SG, and PC designed, researched, and revised the manuscript strictly. QR, FL, and PC analyzed the data set and wrote the manuscript. All authors approved the final version to be published.This study was supported, in part, by research funding from the National Key R&D Program of China (Grant No. 2017YFC0907001), the National Natural Science Foundation of Shanghai (Grant No. 20ZR1434100), and the Shanghai Municipal Health System Important and Weak Discipline  Project (Grant No. 2019ZB0104).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.Figures S1‐S8Click here for additional data file.Table S1Click here for additional data file.Table S2Click here for additional data file.Table S3Click here for additional data file.Table S4Click here for additional data file.