Risk-reducing mastectomy and breast cancer mortality in women with a BRCA1 or BRCA2 pathogenic variant: an international analysis.

BACKGROUND: Risk-reducing mastectomy (RRM) is offered to women with a BRCA1 or BRCA2 pathogenic variant, however, there are limited data on the impact on breast cancer mortality. METHODS: Participants were identified from a registry of women with BRCA1/2 pathogenic variants. We used a pseudo-randomised trial design and matched one woman with a RRM to one woman without a RRM on year of birth, gene, and country. We estimated the hazard ratio (HR) and 95% confidence intervals (CI) for dying of breast cancer in the follow-up period. RESULTS: There were 1654 women included; 827 assigned to the RRM arm and 827 assigned to the control arm. After a mean follow-up of 6.3 years, there were 20 incident breast cancers (including 15 occult cancers) and two breast cancer deaths in the RRM arm, and 100 incident breast cancers and 7 breast cancer deaths in the control arm (HR = 0.26; 95% CI 0.05-1.35; p = 0.11). The probability of dying of breast cancer within 15 years after RRM was 0.95%. CONCLUSIONS: In women with a BRCA1 or BRCA2 pathogenic variant, RRM reduces the risk of breast cancer, and the probability of dying of breast cancer is low.

Incidence of endometrial cancer in BRCA mutation carriers.

OBJECTIVE: Whether or not women who harbor a germline pathogenic variant ('mutation') in the BRCA1 or BRCA2 genes are at elevated risk of developing endometrial cancer is yet to be determined. METHODS: We conducted a prospective analysis of 4959 BRCA mutation carriers with no prior history of cancer (except for breast or melanoma) and an intact uterus. RESULTS: After a mean of 6.7 years of follow-up there were 38 incident cases of endometrial cancer diagnosed; 30 among BRCA1 carriers and eight among BRCA2 carriers. The mean age at diagnosis was 58.4 years (range 46.8-76.1). The majority were of the endometrioid subtype (n = 16), followed by mixed endometroid and serous (n = 4), serous (n = 3) or clear cell (n = 1) (missing = 13). The cumulative incidence from age 40 to age 70 was 3.4% for BRCA1 carriers and was 1.6% for BRCA2 mutation carriers. Prior tamoxifen use was associated with a significant two-fold increased risk (HR = 2.24; 95% CI 1.10-4.55). There was no significant association between exogenous hormone use, oophorectomy, smoking or BMI at age 40 and risk (P ≥ 0.32). CONCLUSIONS: Compared to the general population, we observed higher rates of endometrial cancer among young BRCA1 mutation carriers; however, lifetime risks were similar. Women with prior tamoxifen exposure were at a significantly increased risk. These findings were based. on a small number of incident cases and require confirmation with additional follow-up of our aging cohort.

The risk of skin cancer in women who carry BRCA1 or BRCA2 mutations.

BACKGROUND: It has not been clearly established if skin cancer or melanoma are manifestations of BRCA1 or BRCA2 mutation carrier status. Estimating the risk of skin cancer is an important step towards developing screening recommendations. METHODS: We report the findings of a prospective cohort study of 6,207 women from North America who carry BRCA1 or BRCA2 mutations. Women were followed from the date of baseline questionnaire to the diagnosis of skin cancer, to age 80 years, death from any cause, or the date of last follow-up. RESULTS: During the mean follow-up period of eight years, 3.7% of women with a BRCA1 mutation (133 of 3,623) and 3.8% of women with a BRCA2 mutation (99 of 2,584) reported a diagnosis of skin cancer (including both keratinocyte carcinomas and melanoma). The cumulative risk of all types of skin cancer from age 20 to 80 years was 14.1% for BRCA1 carriers and 10.7% for BRCA2 carriers. The cumulative risk of melanoma was 2.5% for BRCA1 carriers and 2.3% for BRCA2 carriers, compared to 1.5% for women in the general population in the United States. The strongest risk factor for skin cancer was a prior diagnosis of skin cancer. CONCLUSION: The risk of non-melanoma skin cancer in women who carry a mutation in BRCA1 or BRCA2 is similar to that of non-carrier women. The risk of melanoma appears to be slightly elevated. We suggest that a referral to a dermatologist or primary care provider for BRCA mutation carriers for annual skin examination and counselling regarding limiting UV exposure, the use of sunscreen and recognizing the early signs of melanoma might be warranted, but further studies are necessary.

The risks of cancer in older women with BRCA pathogenic variants: How far have we come?

BACKGROUND: The purpose of this study was to estimate the cumulative risks of all cancers in women from 50 to 75 years of age with a BRCA1 or BRCA2 pathogenic variant. METHODS: Participants were women with BRCA1 or BRCA2 pathogenic variants from 85 centers in 16 countries. Women were eligible if they had no cancer before the age of 50 years. Participants completed a baseline questionnaire and follow-up questionnaires every 2 years. Women were followed from age 50 until a diagnosis of cancer, death, age 75, or last follow-up. The risk of all cancers combined from age 50 to 75 was estimated using the Kaplan-Meier method. RESULTS: There were 2211 women included (1470 BRCA1 and 742 BRCA2). There were 379 cancers diagnosed in the cohort between 50 and 75 years. The actuarial risk of any cancer from age 50 to 75 was 49% for BRCA1 and 43% for BRCA2. Breast (n = 186) and ovarian (n = 45) were the most frequent cancers observed. For women who had both risk-reducing mastectomy and bilateral salpingo-oophorectomy before age 50, the risk of developing any cancer between age 50 and 75 was 9%. CONCLUSION: Women with a BRCA1 or BRCA2 pathogenic variant have a high risk of cancer between the ages of 50 and 75 years and should be counselled appropriately.

Tamoxifen and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation.

PURPOSE: Chemoprevention with a selective estrogen receptor modulator (tamoxifen or raloxifene) is a non-surgical option offered to high-risk women to reduce the risk of breast cancer. The evidence for tamoxifen benefit is based on trials conducted among predominantly postmenopausal women from the general population and on studies of contralateral breast cancer in women with a pathogenic variant (mutation hereafter) in BRCA1 or BRCA2. Tamoxifen has not been assessed as a primary prevention agent in women with an inherited BRCA mutation. METHODS: We conducted a prospective analysis of tamoxifen chemoprevention and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation. Data on tamoxifen (and raloxifene) use was collected by questionnaire and updated biennially. Information on incident cancers was collected by self-report and was confirmed by medical record review. In a matched analysis, we estimated the hazard ratio (HR) and 95% confidence intervals (CI) for developing a first primary breast cancer associated with tamoxifen or raloxifene use, using Cox proportional hazards analysis. RESULTS: There were 4578 unaffected women in the cohort, of whom 137 reported tamoxifen use (3%), 83 reported raloxifene use (2%) and 12 used both drugs (0.3%). Women who used tamoxifen or raloxifene were matched 1:3 with women who used neither drug on year of birth, country of residence, year of study entry and gene (BRCA1 or BRCA2). We generated 202 matched pairs. After a mean follow-up of 6.8 years, there were 22 incident breast cancers diagnosed among tamoxifen/raloxifene users (10.9% of users) and 71 cases diagnosed among non-users (14.3% of non-users; HR = 0.64; 95% CI 0.40-1.03; P = 0.07). CONCLUSION: Chemoprevention may be an effective risk-reduction option for BRCA mutation carriers, but further studies with longer follow-up are necessary.

Iron Status and Associated Factors among Canadian Women: Results from the Canadian Health Measures Survey.

BACKGROUND: Iron deficiency and overload may negatively impact women's health. There has been limited assessment of iron status and its associated factors among Canadian women. OBJECTIVES: This study investigated associations of various sociodemographic, lifestyle, medication, and dietary factors with body iron stores among pre- and postmenopausal women in Canada. METHODS: Analyses were conducted using cross-sectional, nationally representative survey and biomarker data from women aged 20-79 y (n = 6362) in the Canadian Health Measures Survey (2009-2017). Body iron stores were assessed by measuring serum concentrations of ferritin (SF). Information on potential correlates was collected during an in-home interview. Multivariable linear regression analyses were performed to evaluate associations with SF concentration, and logistic regression was used to estimate associations with iron deficiency (SF <15 µg/L) or elevated iron stores (SF >150 µg/L). RESULTS: Geometric mean SF concentrations were significantly higher in postmenopausal than in premenopausal women (73.2 versus 33.8 µg/L; P < 0.001). The prevalence of iron deficiency among pre- and postmenopausal women was 16.0% and 4.0%, respectively, whereas that of elevated iron stores was 2.7% and 21.0%, respectively. After simultaneous adjustment for multiple factors, including high-sensitivity CRP (inflammation marker), we found that age, East/Southeast Asian (versus White) race/ethnicity, alcohol, and red meat consumption were positively associated with SF concentration among pre- and postmenopausal women. In addition, aspirin use and dairy consumption were inversely associated with SF concentration among postmenopausal women only. Similar patterns were observed for associations with elevated iron stores among postmenopausal women, whereas higher grain consumption was associated with an increased prevalence of iron deficiency among premenopausal women. CONCLUSIONS: Sociodemographic, lifestyle, medication, and dietary factors are correlated with iron status determined by SF concentration among Canadian women. The findings may have implications for intervention strategies aimed at optimizing body iron stores in pre- and postmenopausal women.

Care after premenopausal risk-reducing salpingo-oophorectomy in high-risk women: Scoping review and international consensus recommendations.

Women at high inherited risk of ovarian cancer are offered risk-reducing salpingo-oophorectomy (RRSO) from age 35 to 45 years. Although potentially life-saving, RRSO may induce symptoms that negatively affect quality of life and impair long-term health. Clinical care following RRSO is often suboptimal. This scoping review describes how RRSO affects short- and long-term health and provides evidence-based international consensus recommendations for care from preoperative counselling to long-term disease prevention. This includes the efficacy and safety of hormonal and non-hormonal treatments for vasomotor symptoms, sleep disturbance and sexual dysfunction and effective approaches to prevent bone and cardiovascular disease.

Evaluating the Utility of ctDNA in Detecting Residual Cancer and Predicting Recurrence in Patients with Serous Ovarian Cancer.

Ovarian cancer has a high case fatality rate, but patients who have no visible residual disease after surgery have a relatively good prognosis. The presence of any cancer cells left in the peritoneal cavity after treatment may precipitate a cancer recurrence. In many cases, these cells are occult and are not visible to the surgeon. Analysis of circulating tumour DNA in the blood (ctDNA) may offer a sensitive method to predict the presence of occult (non-visible) residual disease after surgery and may help predict disease recurrence. We assessed 48 women diagnosed with serous ovarian cancer (47 high-grade and 1 low-grade) for visible residual disease and for ctDNA. Plasma, formalin-fixed paraffin-embedded (FFPE) tumour tissue and white blood cells were used to extract circulating free DNA (cfDNA), tumour DNA and germline DNA, respectively. We sequenced DNA samples for 59 breast and ovarian cancer driver genes. The plasma sample was collected after surgery and before initiating chemotherapy. We compared survival in women with no residual disease, with and without a positive plasma ctDNA test. We found tumour-specific variants (TSVs) in cancer cells from 47 patients, and these variants were sought in ctDNA in their post-surgery plasma. Fifteen (31.9%) of the 47 patients had visible residual disease; of these, all 15 had detectable ctDNA. Thirty-one patients (65.9%) had no visible residual disease; of these, 24 (77.4%) patients had detectable ctDNA. Of the patients with no visible residual disease, those patients with detectable ctDNA had higher mortality (20 of 27 died) than those without detectable ctDNA (3 of 7 died) (HR 2.32; 95% CI: 0.67-8.05), although this difference was not statistically significant (p = 0.18). ctDNA in post-surgical serum samples may predict the presence of microscopic residual disease and may be a predictor of recurrence among women with ovarian cancer. Larger studies are necessary to validate these findings.

Impact of germline mutations in cancer-predisposing genes on long-term survival in patients with epithelial ovarian cancer.

BACKGROUND: Several clinical and tumour factors impact on ovarian cancer survival. It is important to evaluate if germline mutations impact long-term outcomes among patients with epithelial ovarian cancer. METHODS: We followed 1422 Ontario women with ovarian cancer. Clinical information was obtained from medical records and vital status was determined by registry linkage. Germline genetic testing was performed for 12 susceptibility genes. We estimated 20-year cancer-specific survival according to various factors. RESULTS: Twenty-year survival was inferior for women with serous cancers vs. other types (22.3% vs. 68.6%; P < 0.0001). Of the 1422 patients, 248 (17.4%) carried a germline mutation; 119 BRCA1; 75 BRCA2; 7 in a mismatch repair (MMR) gene and 47 in one of seven other genes. Among serous patients, 20-year survival was 28.9% for similar for women with a BRCA1 (28.9%), BRCA2 (21.2%) or no mutation (21.6%). Among endometrioid patients, 20-year survival was poor for women with a BRCA vs. no mutation (47.3% vs. 70.4%; P = 0.004). Six of the seven MMR mutation carriers are currently alive, while all three PALB2 mutation carriers died within 3 years of diagnosis. Among women with Stage III/IV serous cancers, 20-year survival was 9.4% for those with vs. 46.5% for those with no residual disease (HR = 2.91; 95% CI 2.12-4.09, P < 0.0001). CONCLUSIONS: The most important predictor of long-term survival was no residual disease post surgery. BRCA mutation status was not predictive of long-term survival while those with MMR mutations had excellent survival. Larger studies on PALB2 carriers are needed.

Contraceptive use and the risk of ovarian cancer among women with a BRCA1 or BRCA2 mutation.

Background BRCA1 and BRCA2 (BRCA) mutation carriers face a high lifetime risk of developing ovarian cancer. Oral contraceptives are protective in this population; however, the impact of other types of contraception (e.g. intrauterine devices, implants, injections) is unknown. We undertook a matched case-control study to evaluate the relationship between type of contraception and risk of ovarian cancer among women with BRCA mutations. Methods A total of 1733 matched pairs were included in this analysis. Women were matched according to year of birth, date of study entry, country of residence, BRCA mutation type and history of breast cancer. Detailed information on hormonal, reproductive and lifestyle exposures were collected from a routinely administered questionnaire. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) associated with each contraceptive exposure. Results Ever use of any contraceptive was significantly associated with reduced risk of ovarian cancer (OR = 0.62; 95% CI 0.52-0.75; P < 0.0001), which was driven by significant inverse associations with oral contraceptives (OR = 0.66; 95% CI 0.54-0.79; P < 0.0001) and contraceptive implants (OR = 0.30; 95% CI 0.12-0.73; P = 0.008). We observed a similar effect with use of injections (OR = 0.37; 95% CI 0.10-1.38; P = 0.14), but this did not achieve significance. No significant associations were observed between patterns of intrauterine device use and risk of ovarian cancer. Conclusions These findings support a protective effect of oral contraceptives and implants on risk of ovarian cancer among women with BRCA mutations. The possible protective effect of injections requires further evaluation.

Tubal histopathological abnormalities in BRCA1/2 mutation carriers undergoing prophylactic salpingo-oophorectomy: a case-control study.

OBJECTIVE: To describe tubal histopathological abnormalities in women with germline BRCA1/2 mutations and in controls. METHODS: Consecutive women with BRCA1/2 mutations undergoing bilateral salpingo-oophorectomy between 2010 and 2020 in two centers (San Gerardo Hospital, Monza and San Matteo Hospital, Pavia) were considered in this analysis and compared with controls who had the same surgical procedure for benign conditions. Frequency of p53 signature, serous tubal intraepithelial carcinoma, and high-grade serous ovarian cancer were compared between the two groups. RESULTS: A total of 194 women with pathogenic BRCA1/2 mutations underwent prophylactic salpingo-oophorectomy. Of these, 138 women (71%) had a completely negative histological examination, while in 56 (29%) patients an ovarian or tubal alteration was reported. Among controls, 84% of patients had a p53wt signature, while 16% had a p53 signature. There was no difference in the frequency of a p53 signature between cases and controls; however, women with BRCA1/2 mutations were more likely to have pre-malignant or invasive alterations of tubal or ovarian epithelium (p=0.015). Among mutation carriers, older age both at genetic testing and at surgery was associated with an increased risk of having malignancies (OR=1.07, p=0.006 and OR=1.08, p=0.004, respectively). The risk of malignancy seems to be increased in patients with a familial history of high-grade serous ovarian cancer. Previous therapy with tamoxifen was significantly more frequent in patients with malignant lesions (40.0% vs 21.3%, p=0.006). CONCLUSION: We found that a p53 signature is a frequent finding both in BRCA1/2 mutation carriers and in controls, while pre-invasive and invasive lesions are more frequent in BRCA1/2 mutation carriers. Genetic and clinical characteristics are likely to affect the progression to malignancy.

Beyond the pill: contraception and the prevention of hereditary ovarian cancer.

BRCA1 and BRCA2 mutation carriers face an elevated lifetime risk of developing ovarian cancer. Oral contraceptives have been shown to significantly decrease the risk of ovarian cancer by approximately 50% in this high-risk population. Changes in contraceptive formulations and patterns of use over time have introduced lower hormonal dosages, different steroid types and non-oral routes of administration. Specifically, there has been a considerable shift in patterns of contraceptive use and the increase in the uptake of non-oral, long-acting, reversible contraception (e.g., intrauterine devices, implants, injections) has corresponded to a decline in oral contraceptive pill use. Whether or not these other methods confer a protective effect against ovarian cancer in the general population is not clear. To our knowledge, there have been no such studies conducted among BRCA mutation carriers. Furthermore, the impact of these changes on the risk of developing ovarian cancer is not known. In this article, we will review the existing epidemiologic evidence regarding the role of contraceptives and the risk of ovarian cancer with a focus on women with a BRCA1 or BRCA2 mutation. We will discuss recent findings and gaps in the knowledge while extrapolating from studies conducted among women from the noncarrier population.

Delineating the role of osteoprotegerin as a marker of breast cancer risk among women with a BRCA1 mutation.

Women with a pathogenic germline mutation in the BRCA1 gene face a very high lifetime risk of developing breast cancer, estimated at 72% by age 80. Prophylactic bilateral mastectomy is the only effective way to lower their risk; however, most women with a mutation opt for intensive screening with annual MRI and mammography. Given that the BRCA1 gene was identified over 20 years ago, there is a need to identify a novel non-surgical approach to hereditary breast cancer prevention. Here, we provide a review of the emerging preclinical and epidemiologic evidence implicating the dysregulation of progesterone-mediated receptor activator of nuclear factor κB (RANK) signaling in the pathogenesis of BRCA1-associated breast cancer. Experimental studies have demonstrated that RANK inhibition suppresses Brca1-mammary tumorigenesis, suggesting a potential target for prevention. Data from studies conducted among women with a BRCA1 mutation further support this pathway in BRCA1-associated breast cancer development. Progesterone-containing (but not estrogen-alone) hormone replacement therapy is associated with an increased risk of breast cancer in women with a BRCA1 mutation. Furthermore, BRCA1 mutation carriers have significantly lower levels of circulating osteoprotegerin (OPG), the decoy receptor for RANK-ligand (RANKL) and thus endogenous inhibitor of RANK signaling. OPG levels may be associated with the risk of disease, suggesting a role of this protein as a potential biomarker of breast cancer risk. This may improve upon current risk prediction models, stratifying women at the highest risk of developing the disease, and further identify those who may be targets for anti-RANKL chemoprevention. Collectively, the evidence supports therapeutic inhibition of the RANK pathway for the primary prevention of BRCA1-associated breast cancer, which may generate unique prevention strategies (without prophylactic surgery) and enhance quality of life.

An evaluation of memory and attention in BRCA mutation carriers using an online cognitive assessment tool.

BACKGROUND: The objective of this study was to evaluate the impact of various surgical, hormonal, and lifestyle factors on memory and attention in women with a BRCA1 or BRCA2 mutation. METHODS: BRCA mutation carriers enrolled in a longitudinal study were invited to complete an online brain health assessment tool designed to screen for cognitive deficits. Four measures of memory and executive attention were assessed individually, and an overall score was compiled adjusting for age. Exposures, including preventive surgery, hormone use, and lifestyle factors, were captured by questionnaire. Performance on each of the 5 subtasks was analyzed according to various exposures. Analysis of covariance was used to compare overall scores. RESULTS: In total, 880 women completed the online cognitive assessment. The average age of the participants was 54 years (range, 23-86 years). The mean overall test score was 54.4 (range, 0-93). The individual subtask scores declined with age at test completion (P < .0001) and increased with level of education (P ≤ .01). Women who underwent a preventive oophorectomy had a significantly higher overall score compared with women who did not undergo this surgery (55.5 vs 50.5; P = .01). Reconstructive breast surgery was also associated with a higher overall score (56.5 vs 52.3; P = .005). Chemotherapy and hormone-replacement therapy were not predictive of the overall score. CONCLUSIONS: These findings are reassuring to high-risk women who undergo early surgical menopause for their cancer predisposition. Further studies are needed to evaluate cognitive function over time when memory deficits become more prevalent.

Breast cancer risk after age 60 among BRCA1 and BRCA2 mutation carriers.

PURPOSE: It is not known whether the risk of breast cancer among BRCA1 and BRCA2 mutation carriers after age 60 is high enough to justify intensive screening or prophylactic surgery. Thus, we conducted a prospective analysis of breast cancer risk in BRCA1 and BRCA2 mutation carriers from age 60 until age 80. METHODS: Subjects had no history of cancer and both breasts intact at age 60 (n = 699). Women were followed until a breast cancer diagnosis, prophylactic bilateral mastectomy or death. We calculated the annual cancer rate and cumulative incidence of breast cancer (invasive and in situ) from age 60 to age 80. We assessed the associations between hormone replacement therapy, family history of breast cancer and bilateral oophorectomy and breast cancer risk. RESULTS: Over a mean follow-up of 7.9 years, 61 invasive and 20 in situ breast cancers were diagnosed in the cohort. The mean annual rate of invasive breast cancer was 1.8% for BRCA1 mutation carriers and 1.7% for BRCA2 mutation carriers. The cumulative risk of invasive breast cancer from age 60 to 80 was 20.1% for women with a BRCA1 mutation and was 17.3% for women with a BRCA2 mutation. Hormone replacement therapy, family history and oophorectomy were not associated with breast cancer risk. CONCLUSIONS: Findings from this large prospective study indicate that the risk of developing breast cancer remains high after age 60 in both BRCA1 and BRCA2 mutation carriers. These findings warrant further evaluation of the role of breast cancer screening in older mutation carriers.

Prophylactic salpingectomy for the prevention of ovarian cancer: Who should we target?

Ovarian cancer is the most fatal gynecologic malignancy (50% 5-year survival) due to a typically advanced stage at diagnosis and a high rate of recurrence. Chemoprevention options are limited, and few interventions have been shown to reduce cancer risk or mortality. Emerging data support the model that fallopian tubes are the site of origin for a proportion of high-grade serous cancers. This implies that a subset of cancers may be prevented by removing the fallopian tubes while leaving the ovaries intact. Accordingly, there has been shift in clinical practice for average risk women; some now recommend removal of both the fallopian tubes only instead of tubal ligation for sterilization or at the time of benign gynecologic surgery. This has been termed opportunistic salpingectomy and represents a means of decreasing the burden of ovarian cancer by preventing cancers that arise in the fallopian tubes. There have been no detailed, prospective reports that have estimated ovarian cancer risk reduction with opportunistic salpingectomy, neither among women at baseline population risk nor among women at a high risk of developing the disease. The situation is complicated for women with a BRCA mutation-bilateral salpingo-oophorectomy is a proven means of risk reduction and salpingectomy alone is not the standard of care. Based on the existing data, salpingectomy alone should only be reserved for women with a lifetime risk of ovarian cancer of less than 5%.

Iron intake, oxidative stress-related genes and breast cancer risk.

Iron has been suggested to contribute to breast cancer development through oxidative stress generation. Our study investigated associations between iron intake and breast cancer risk, overall and by menopausal and estrogen receptor/progesterone receptor (ER/PR) status, and modification by oxidative stress-related genetic polymorphisms (MnSOD, GSTM1 and GSTT1). A population-based case-control study (3,030 cases and 3,402 controls) was conducted in Ontario, Canada. Iron intake (total, dietary, supplemental, heme, nonheme) was assessed using a validated food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from multivariable logistic regression models. Interactions between iron intake and genotypes were assessed among 1,696 cases and 1,761 controls providing DNA. Overall, no associations were observed between iron intake and breast cancer risk. Among premenopausal women, total, dietary and dietary nonheme iron were positively associated with ER-/PR- breast cancer risk (all ptrend < 0.05). Among postmenopausal women, supplemental iron was associated with reduced breast cancer risk (OR>18 vs. 0 mg/day = 0.68, 95% CI: 0.51-0.91), and dietary heme iron was associated with an increased risk, particularly the ER-/PR- subtype (ORhighest vs. lowest quintile = 1.69, 95% CI: 1.16-2.47; ptrend = 0.02). Furthermore, GSTT1 and combined GSTM1/GSTT1 polymorphisms modified some of the associations. For example, higher dietary iron was most strongly associated with increased breast cancer risk among women with GSTT1 deletion or GSTM1/GSTT1 double deletions (pinteraction < 0.05). Findings suggest that iron intake may have different effects on breast cancer risk according to menopausal and hormone receptor status, as well as genotypes affecting antioxidant capacity.

Blood arsenic levels and the risk of familial breast cancer in Poland.

Arsenic is recognized as a potent carcinogen at high concentrations, but the relationship between environmental arsenic and breast cancer risk has not well been studied. Most research has focused on the effect of arsenic in populations with high endemic exposure, and not in populations with arsenic levels within normal limits. We sought to determine if blood arsenic levels predict the risk of breast and other cancers risk among women in northern Poland. The cohort consisted of 1,702 healthy women, aged 40 and above, identified between 2010 and 2017. Blood arsenic level was determined by inductively coupled plasma mass spectrometry. After an average of 4.5 years of follow-up (range 0.7-7.3 years), there were 110 incident cases of cancer diagnosed in the cohort, including 68 cases of breast cancer. Women in the highest quartile of arsenic had a highly significant 13-fold increased risk of developing breast cancer, compared to women in the lowest quartile (hazard ratio [HR] = 13.2; 95% confidence interval [CI] 4.02-43.0). Results were similar for arsenic and all incident cancers (HR quartile 4 vs. quartile 1 = 13.3; 95% CI 4.78-37.0). If confirmed, our study suggests that the blood arsenic level may be a useful predictive marker of cancer risk in women.

Breastfeeding and the risk of epithelial ovarian cancer among women with a BRCA1 or BRCA2 mutation.

OBJECTIVE: BRCA mutation carriers face a high lifetime risk of developing ovarian cancer. The strong inverse association between breastfeeding and the risk of ovarian cancer is established in the general population but is less well studied among women with a germline BRCA1 or BRCA2 mutation. METHOD: Thus, we conducted a matched case-control analysis to evaluate the association between breastfeeding history and the risk of developing ovarian cancer. After matching for year of birth, country of residence, BRCA gene and personal history of breast cancer, a total of 1650 cases and 2702 controls were included in the analysis. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI) associated with various breastfeeding exposures. RESULTS: A history of ever-breastfeeding was associated with a 23% reduction in risk (OR = 0.77; 95%CI 0.66-0.90; P = 0.001). The protective effect increased with breastfeeding from one month to seven months after which the association was relatively stable. Compared to women who never breastfed, breastfeeding for seven or more months was associated with a 32% reduction in risk (OR = 0.68; 95%CI 0.57-0.81; P < 0.0001) and did not vary by BRCA gene or age at diagnosis. The combination of breastfeeding and oral contraceptive use was strongly protective (0.47; 95%CI 0.37-0.58; P < 0.0001). CONCLUSIONS: These findings support a protective effect of breastfeeding for at least seven months among women with a BRCA1 or BRCA2 mutation, that is independent of oral contraceptive use.

Long-term outcomes following a diagnosis of ovarian cancer at the time of preventive oophorectomy among BRCA1 and BRCA2 mutation carriers.

INTRODUCTION: Preventive bilateral salpingo-oophorectomy is the most effective means of reducing the risk of ovarian cancer among women with an inherited BRCA1 or BRCA2 mutation. Some women are diagnosed with an invasive cancer (ovarian or fallopian tube) at the time of preventive surgery, referred to as an 'occult' cancer. The survival experience of these women is not known. METHODS: We estimated the 10-year survival for 52 BRCA mutation carriers diagnosed with an occult ovarian or fallopian tube cancer at the time of preventive bilateral salpingo-oophorectomy. RESULTS: The mean age at diagnosis was 51.6 (range 33-69) years. All were serous cancers (although 14 were missing information on histologic subtype). Of the 20 cases with information available on stage at diagnosis, 10 were stage I, 1 was stage II, and 9 were stage III (n=32 missing). After a mean of 6.8 years, 12 women died (23%). The 10-year all-cause survival was 74%. CONCLUSION: Although based on only 52 cases, these findings suggest a more favorable prognosis for BRCA mutation carriers diagnosed with an occult rather than incident disease.