Oophorectomy and risk of contralateral breast cancer among BRCA1 and BRCA2 mutation carriers

Bilateral Oophorectomy and All-Cause Mortality in Women With BRCA1 and BRCA2 Sequence Variations

Importance

Preventive bilateral salpingo-oophorectomy is offered to women at high risk of ovarian cancer who carry a pathogenic variant in BRCA1 or BRCA2; however, the association of oophorectomy with all-cause mortality has not been clearly defined.

Objective

To evaluate the association between bilateral oophorectomy and all-cause mortality among women with a BRCA1 or BRCA2 sequence variation.

Design, Setting, and Participants

In this international, longitudinal cohort study of women with BRCA sequence variations, information on bilateral oophorectomy was obtained via biennial questionnaire. Participants were women with a BRCA1 or BRCA2 sequence variation, no prior history of cancer, and at least 1 follow-up questionnaire completed. Women were followed up from age 35 to 75 years for incident cancers and deaths. Cox proportional hazards regression was used to estimate the hazard ratios (HRs) and 95% CIs for all-cause mortality associated with a bilateral oophorectomy (time dependent). Data analysis was performed from January 1 to June 1, 2023.

Exposures

Self-reported bilateral oophorectomy (with or without salpingectomy).

Main Outcomes and Measures

All-cause mortality, breast cancer-specific mortality, and ovarian cancer-specific mortality.

Results

There were 4332 women (mean age, 42.6 years) enrolled in the cohort, of whom 2932 (67.8%) chose to undergo a preventive oophorectomy at a mean (range) age of 45.4 (23.0-77.0) years. After a mean follow-up of 9.0 years, 851 women had developed cancer and 228 had died; 57 died of ovarian or fallopian tube cancer, 58 died of breast cancer, 16 died of peritoneal cancer, and 97 died of other causes. The age-adjusted HR for all-cause mortality associated with oophorectomy was 0.32 (95% CI, 0.24-0.42; P < .001). The age-adjusted HR was 0.28 (95% CI, 0.20-0.38; P < .001) and 0.43 (95% CI, 0.22-0.90; P = .03) for women with BRCA1 and BRCA2 sequence variations, respectively. For women with BRCA1 sequence variations, the estimated cumulative all-cause mortality to age 75 years for women who had an oophorectomy at age 35 years was 25%, compared to 62% for women who did not have an oophorectomy. For women with BRCA2 sequence variations, the estimated cumulative all-cause mortality to age 75 years was 14% for women who had an oophorectomy at age 35 years compared to 28% for women who did not have an oophorectomy.

Conclusions and Relevance

In this cohort study among women with a BRCA1 or BRCA2 sequence variation, oophorectomy was associated with a significant reduction in all-cause mortality.

Vitamin D and Calcium Supplement Use and High-Risk Breast Cancer: A Case-Control Study among BRCA1 and BRCA2 Mutation Carriers

The role of vitamin D and calcium use in the development of breast cancer among women in the general population is not clear. Furthermore, whether vitamin D and calcium supplement use are associated with breast cancer in high-risk populations has not been evaluated. Thus, we evaluated the association between vitamin D and/or calcium supplement use and breast cancer among women with a pathogenic variant (mutation) in BRCA1 or BRCA2. BRCA mutation carriers enrolled in a longitudinal study were invited to complete a supplemental questionnaire on lifetime supplement use. Cases included women with a prevalent diagnosis of invasive breast cancer, and controls had no history of breast cancer. Vitamin D and calcium use were categorized as never/ever use, and as tertiles of supplement intake (total average daily supplement use). Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CIs) of breast cancer. This study included 134 breast cancer cases and 276 controls. Women who used vitamin D-containing supplements had 46% lower odds of having breast cancer compared to those who never used supplements (OR 0.54; 95% CI 0.31, 0.91; p = 0.02). Increasing vitamin D and calcium supplement intake was inversely associated with the odds of having breast cancer (p-trend = 0.04). Findings were suggestively stronger among BRCA1 mutation carriers; however, analyses were limited by small strata. These findings suggest a potential inverse association between vitamin D and calcium supplementation and BRCA breast cancer. Additional studies are warranted to confirm these findings and accurately inform clinical care guidelines.

Contralateral Breast Cancer Risk Among Carriers of Germline Pathogenic Variants in ATM, BRCA1, BRCA2, CHEK2, and PALB2

PURPOSE

To estimate the risk of contralateral breast cancer (CBC) among women with germline pathogenic variants (PVs) in ATM, BRCA1, BRCA2, CHEK2, and PALB2.

METHODS

The study population included 15,104 prospectively followed women within the CARRIERS study treated with ipsilateral surgery for invasive breast cancer. The risk of CBC was estimated for PV carriers in each gene compared with women without PVs in a multivariate proportional hazard regression analysis accounting for the competing risk of death and adjusting for patient and tumor characteristics. The primary analyses focused on the overall cohort and on women from the general population. Secondary analyses examined associations by race/ethnicity, age at primary breast cancer diagnosis, menopausal status, and tumor estrogen receptor (ER) status.

RESULTS

Germline BRCA1, BRCA2, and CHEK2 PV carriers with breast cancer were at significantly elevated risk (hazard ratio > 1.9) of CBC, whereas only the PALB2 PV carriers with ER-negative breast cancer had elevated risks (hazard ratio, 2.9). By contrast, ATM PV carriers did not have significantly increased CBC risks. African American PV carriers had similarly elevated risks of CBC as non-Hispanic White PV carriers. Among premenopausal women, the 10-year cumulative incidence of CBC was estimated to be 33% for BRCA1, 27% for BRCA2, and 13% for CHEK2 PV carriers with breast cancer and 35% for PALB2 PV carriers with ER-negative breast cancer. The 10-year cumulative incidence of CBC among postmenopausal PV carriers was 12% for BRCA1, 9% for BRCA2, and 4% for CHEK2.

CONCLUSION

Women diagnosed with breast cancer and known to carry germline PVs in BRCA1, BRCA2, CHEK2, or PALB2 are at substantially increased risk of CBC and may benefit from enhanced surveillance and risk reduction strategies.

Breast Cancer Risk and Breast-Cancer-Specific Mortality following Risk-Reducing Salpingo-Oophorectomy in BRCA Carriers: A Systematic Review and Meta-Analysis

BACKGROUND

Risk-reducing salpingo-oophorectomy (RRSO) is the gold standard method of ovarian cancer risk reduction, but the data are conflicting regarding the impact on breast cancer (BC) outcomes. This study aimed to quantify BC risk/mortality in BRCA1/BRCA2 carriers after RRSO.

METHODS

We conducted a systematic review (CRD42018077613) of BRCA1/BRCA2 carriers undergoing RRSO, with the outcomes including primary BC (PBC), contralateral BC (CBC) and BC-specific mortality (BCSM) using a fixed-effects meta-analysis, with subgroup analyses stratified by mutation and menopause status.

RESULTS

RRSO was not associated with a significant reduction in the PBC risk (RR = 0.84, 95%CI: 0.59-1.21) or CBC risk (RR = 0.95, 95%CI: 0.65-1.39) in BRCA1 and BRCA2 carriers combined but was associated with reduced BC-specific mortality in BC-affected BRCA1 and BRCA2 carriers combined (RR = 0.26, 95%CI: 0.18-0.39). Subgroup analyses showed that RRSO was not associated with a reduction in the PBC risk (RR = 0.89, 95%CI: 0.68-1.17) or CBC risk (RR = 0.85, 95%CI: 0.59-1.24) in BRCA1 carriers nor a reduction in the CBC risk in BRCA2 carriers (RR = 0.35, 95%CI: 0.07-1.74) but was associated with a reduction in the PBC risk in BRCA2 carriers (RR = 0.63, 95%CI: 0.41-0.97) and BCSM in BC-affected BRCA1 carriers (RR = 0.46, 95%CI: 0.30-0.70). The mean NNT = 20.6 RRSOs to prevent one PBC death in BRCA2 carriers, while 5.6 and 14.2 RRSOs may prevent one BC death in BC-affected BRCA1 and BRCA2 carriers combined and BRCA1 carriers, respectively.

CONCLUSIONS

RRSO was not associated with PBC or CBC risk reduction in BRCA1 and BRCA2 carriers combined but was associated with improved BC survival in BC-affected BRCA1 and BRCA2 carriers combined and BRCA1 carriers and a reduced PBC risk in BRCA2 carriers.

Effectiveness of Secondary Risk-Reducing Strategies in Patients With Unilateral Breast Cancer With Pathogenic Variants of BRCA1 and BRCA2 Subjected to Breast-Conserving Surgery: Evidence-Based Simulation Study

BACKGROUND

Approximately 62% of patients with breast cancer with a pathogenic variant (BRCA1 or BRCA2) undergo primary breast-conserving therapy.

OBJECTIVE

The study aims to develop a personalized risk management decision support tool for carriers of a pathogenic variant (BRCA1 or BRCA2) who underwent breast-conserving therapy for unilateral early-stage breast cancer.

METHODS

We developed a Bayesian network model of a hypothetical cohort of carriers of BRCA1 or BRCA2 diagnosed with stage I/II unilateral breast cancer and treated with breast-conserving treatment who underwent subsequent second primary cancer risk-reducing strategies. Using event dependencies structured according to expert knowledge and conditional probabilities obtained from published evidence, we predicted the 40-year overall survival rate of different risk-reducing strategies for 144 cohorts of women defined by the type of pathogenic variants (BRCA1 or BRCA2), age at primary breast cancer diagnosis, breast cancer subtype, stage of primary breast cancer, and presence or absence of adjuvant chemotherapy.

RESULTS

Absence of adjuvant chemotherapy was the most powerful factor that was linked to a dramatic decline in survival. There was a negligible decline in the mortality in patients with triple-negative breast cancer, who received no chemotherapy and underwent any secondary risk-reducing strategy, compared with surveillance. The potential survival benefit from any risk-reducing strategy was more modest in patients with triple-negative breast cancer who received chemotherapy compared with patients with luminal breast cancer. However, most patients with triple-negative breast cancer in stage I benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy or just risk-reducing salpingo-oophorectomy. Most patients with luminal stage I/II unilateral breast cancer benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy. The impact of risk-reducing salpingo-oophorectomy in patients with luminal breast cancer in stage I/II increased with age. Most older patients with the BRCA1 and BRCA2 pathogenic variants in exons 12-24/25 with luminal breast cancer may gain a similar survival benefit from other risk-reducing strategies or surveillance.

CONCLUSIONS

Our study showed that it is mandatory to consider the complex interplay between the types of BRCA1 and BRCA2 pathogenic variants, age at primary breast cancer diagnosis, breast cancer subtype and stage, and received systemic treatment. As no prospective study results are available at the moment, our simulation model, which will integrate a decision support system in the near future, could facilitate the conversation between the health care provider and patient and help to weigh all the options for risk-reducing strategies leading to a more balanced decision.

Bilateral Oophorectomy and the Risk of Breast Cancer in BRCA1 Mutation Carriers: A Reappraisal

BACKGROUND

The lack of consensus on whether bilateral oophorectomy impacts risk of developing breast cancer among BRCA1 mutation carriers might be attributed to various biases, specifically, cancer-induced testing bias due to inclusion of prevalent cases. We conducted two complementary matched case-control analyses to evaluate the association of oophorectomy and BRCA1 breast cancer.

METHODS

A research questionnaire was administered every two years to collect information on exposures and disease. In the first analysis, we limited the study to prevalent breast cancer cases (diagnosed prior to study entry; n = 2,962) who were matched to controls on year of birth and country of residence (n = 4,358). In the second approach, we limited to 330 incident cases (diagnosed in the follow-up period) and 1,548 matched controls. Conditional logistic regression was used to estimate the adjusted odds ratios (OR) and 95% confidence intervals (CI) of invasive breast cancer.

RESULTS

In the first approach, there was a significant inverse association between oophorectomy and the risk of developing breast cancer [OR = 0.43; 95% confidence interval (CI), 0.34-0.55; P < 00001]. In the second approach, there was no association between oophorectomy and risk (OR = 1.21; 95% CI, 0.87-1.70; P = 0.26).

CONCLUSIONS

The inclusion of women with a personal history of breast cancer prior to ascertainment likely impacts upon the association of oophorectomy and BRCA1 breast cancer risk.

IMPACT

Oophorectomy is unlikely a determinant of breast cancer risk in BRCA1 mutation carriers but should be offered at age 35 to reduce the risk of ovarian and fallopian tube cancer.

Evaluation of the indication of BRCA1/2 genetic tests in Iranian women and acceptance rate of risk-reducing surgeries in BRCA mutation carriers

BACKGROUND

A higher risk for breast and ovarian cancer has been reported in BRCA carriers and prophylactic surgeries are proposed to reduce this risk. This retrospective cohort study has evaluated the indication of BRCA1/2 genetic tests in Iranian women and the rate of women's acceptance of prophylactic surgeries recommended by the surgeon.

METHODS

Medical records of 147 high-risk women according to NCCN clinical practice guidelines who referred for BRCA mutations testing were assessed. Individual information, indications for BRCA1/2 genetic testing and their results, physician recommendations, and type of accepted surgery were registered. To evaluate the current status of women an active visit follow-up every six months was conducted.

RESULTS

The mean age of women was 43.40 ± 10.94 and the median follow-up time was 1.92 years. Genetic test results showed 49(33.3%) women were positive for either BRCA1/2 mutations. Although the occurrence of breast cancer younger than 40 was the most common indication for genetic tests (26.5%), positive breast cancer history in first-degree relatives and two relatives younger than 50 was the most common indications with positive results. The rate of acceptance of prophylactic mastectomy and bilateral salpingo-oophorectomy was (14.3% and 34.7%) in BRCA mutation carriers.

CONCLUSION

If the onset of breast cancer at a young age (less than 40) will be the only indication for a BRCA analysis, the rate of a positive result (12.8%) is very low. Further studies are warranted to evaluate the age limit for genetic testing in our country. Prophylactic mastectomy acceptance is very low in BRCA1/2 carriers in our centers.

Surgical decision making in premenopausal BRCA carriers considering risk-reducing early salpingectomy or salpingo-oophorectomy: a qualitative study

BACKGROUND

Acceptance of the role of the fallopian tube in 'ovarian' carcinogenesis and the detrimental sequelae of surgical menopause in premenopausal women following risk-reducing salpingo-oophorectomy (RRSO) has resulted in risk-reducing early-salpingectomy with delayed oophorectomy (RRESDO) being proposed as an attractive alternative risk-reducing strategy in women who decline/delay oophorectomy. We present the results of a qualitative study evaluating the decision-making process among BRCA carriers considering prophylactic surgeries (RRSO/RRESDO) as part of the multicentre PROTECTOR trial (ISRCTN:25173360).

METHODS

In-depth semistructured 1:1 interviews conducted using a predeveloped topic-guide (development informed by literature review and expert consultation) until informational saturation reached. Wording and sequencing of questions were left open with probes used to elicit additional information. All interviews were audio-recorded, transcribed verbatim, transcripts analysed using an inductive theoretical framework and data managed using NVIVO-v12.

RESULTS

Informational saturation was reached following 24 interviews. Seven interconnected themes integral to surgical decision making were identified: fertility/menopause/cancer risk reduction/surgical choices/surgical complications/sequence of ovarian-and-breast prophylactic surgeries/support/satisfaction. Women for whom maximising ovarian cancer risk reduction was relatively more important than early menopause/quality-of-life preferred RRSO, whereas those more concerned about detrimental impact of menopause chose RRESDO. Women managed in specialist familial cancer clinic settings compared with non-specialist settings felt they received better quality care, improved hormone replacement therapy access and were more satisfied.

CONCLUSION

Multiple contextual factors (medical, physical, psychological, social) influence timing of risk-reducing surgeries. RRESDO offers women delaying/declining premenopausal oophorectomy, particularly those concerned about menopausal effects, a degree of ovarian cancer risk reduction while avoiding early menopause. Care of high-risk women should be centralised to centres with specialist familial gynaecological cancer risk management services to provide a better-quality, streamlined, holistic multidisciplinary approach.

Molecular Trajectory of BRCA1 and BRCA2 Mutations

Every cancer carries genomic mutations. Although almost all these mutations arise after fertilization, a minimal count of cancer predisposition mutations are already present at the time of genesis of germ cells. Of the cancer predisposition genes identified to date, BRCA1 and BRCA2 have been determined to be associated with hereditary breast and ovarian cancer syndrome. Such cancer predisposition genes have recently been attracting attention owing to the emergence of molecular genetics, thus, affecting the strategy of cancer prevention, diagnostics, and therapeutics. In this review, we summarize the molecular significance of these two BRCA genes. First, we provide a brief history of BRCA1 and BRCA2, including their identification as cancer predisposition genes and recognition as members in the Fanconi anemia pathway. Next, we describe the molecular function and interaction of BRCA proteins, and thereafter, describe the patterns of BRCA dysfunction. Subsequently, we present emerging evidence on mutational signatures to determine the effects of BRCA disorders on the mutational process in cancer cells. Currently, BRCA genes serve as principal targets for clinical molecular oncology, be they germline or sporadic mutations. Moreover, comprehensive cancer genome analyses enable us to not only recognize the current status of the known cancer driver gene mutations but also divulge the past mutational processes and predict the future biological behavior of cancer through the molecular trajectory of genomic alterations.

Risk of Contralateral Breast Cancer in Women with and without Pathogenic Variants in BRCA1, BRCA2, and TP53 Genes in Women with Very Early-Onset (<36 Years) Breast Cancer

Early age at diagnosis of breast cancer is a known risk factor for hereditary predisposition and some studies show a high risk of contralateral breast cancer in BRCA1 carriers diagnosed at very young ages. However, little is published on the risk of TP53 carriers. 397 women with breast cancer diagnosed <36 years of age were obtained from three sources: (i) a population-based study of 283 women diagnosed sequentially from 1980-1997 in North-West England, (ii) referrals to the Genomic Medicine Department at St Mary's Hospital from 1990-2018, and (iii) individuals from (i) and the Family History Clinic at Wythenshawe Hospital South Manchester who tested negative for pathogenic variants (PV) in all three genes. Sequencing of BRCA1, BRCA2, and TP53 genes was carried out alongside tests for copy number for PV on all referred women. Rates of contralateral breast cancer were censored at death, last assessment, or risk-reducing mastectomy. In total, 47 TP53, 218 BRCA1, and 132 BRCA2 PV carriers were identified with breast cancer diagnosed aged 35 years and under, as well as a representative sample of 261 not known to carry a PV in BRCA1, BRCA2, and TP53. Annual rates of contralateral breast cancer (and percentage of synchronous breast cancers) were TP53: 7.03% (4.3%), BRCA1: 3.57% (1.8%), and BRCA2: 2.63% (1.5%). In non-PV carriers, contralateral rates in isolated presumed/tested non-carrier cases with no family history were 0.56%, and for those with a family history, 0.69%. Contralateral breast cancer rates are substantial in TP53, BRCA1, and BRCA2 PV carriers diagnosed with breast cancer aged 35 and under. Women need to be advised to help make informed decisions on contralateral mastectomy, guided by life expectancy from their index tumor.