Risk-reducing surgery, screening and chemoprevention practices of BRCA1 and BRCA2 mutation carriers: a prospective cohort study

This study prospectively evaluated the utilization of cancer risk management strategies in a multi-institutional cohort of BRCA1 and BRCA2 mutation carriers using a self-report questionnaire. Of 142 unaffected female mutation carriers, 70 (49%) had elected to receive their mutation result. Of those who knew their mutation result, 11% underwent bilateral mastectomy (BM), 29% had bilateral oophorectomy (BO), 78% performed regular breast self-examination (BSE), and 80%, 89%, 67%, and 0% had at least annual clinical breast examination (CBE), mammography, transvaginal ultrasound (TVU), and CA125, respectively. A further 20%, 7%, 0%, 21%, and 75%, respectively, reported never having had these tests. For women who elected not to receive their mutation result, 0% underwent BM, 6% underwent BO, and 77%, 42%, 56%, 7%, and 0% had regular BSE, CBE, mammography, TVU, and CA125, respectively. Only one woman used chemoprevention outside a clinical trial. Uptake of prophylactic surgery and screening was associated with knowing one's mutation status (for all behaviors except BSE), age (for BO and CBE) and residence (for mammography). In this cohort, the minority of mutation carriers utilized risk-reducing surgery or chemoprevention and a substantial minority were not undergoing regular cancer-screening tests.

Abstract P4-13-10: Do BRCA1 and BRCA2 mutation carriers have an earlier natural menopause than their non-carrier relatives: A study from the Kathleen Cuningham Foundation Consortium For Research Into Familial Breast Cancer (kConFab)

BACKGROUND: Limited data from the in vitro fertilisation setting suggest that germline BRCA1 mutations are associated with occult primary ovarian insufficiency. We examined whether carriers of a BRCA1 or BRCA2 mutation have earlier natural menopause than their non-carrier relatives.

PATIENTS AND METHODS: Eligible subjects were female mutation carriers and tested non-carriers from families segregating BRCA1 or BRCA2 mutations enrolled in KConFab. Women who had not been tested for the family mutation and those with primary amenorrhoea were excluded. Data were self-reported using uniform questionnaires completed at cohort entry and every 3 years thereafter. Age at natural menopause (NM) was defined as age at cessation of menses for ≥ 12 months in the absence of other causes. Cox proportional hazards analysis was applied, modelling time in years from birth to NM, adjusting for year of birth (continuous), body mass index (continuous), ever regular cigarette smoking (no, yes), and ever regular alcohol use (no, yes). Analysis time was censored at the earliest of: cessation of menses for 12 months in the absence of other reasons (natural menopause), last follow-up, pelvic surgery including oophorectomy or hysterectomy, commencement of hormone replacement therapy or Tamoxifen as a risk reducing medication, or any cancer diagnosis. Hazard ratios (HR) were estimated as a measure of how rapidly mutation carriers reach natural menopause relative to non-carriers.

RESULTS: No difference was observed in the rate at which carriers and non-carriers went through natural menopause, regardless of the gene mutated in the families. The adjusted hazard ratio estimates were 0.97, (95% CI 0.69–1.35, p = 0.8) for BRCA1 mutation carriers versus non-carriers and 1.02, (95%CI 0.72–1.44, p = 0.9) for BRCA2 mutation carriers versus non-carriers.

Contralateral risk-reducing mastectomy in BRCA1/2 mutation carriers and other high-risk women in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab)

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Background: Contralateral risk-reducing mastectomy (CRRM) reduces contralateral breast cancer (BC) risk by up to 97%. Few studies have examined the prevalence and predictors of CRRM in BC patients at high familial risk of a second primary BC. Methods: Participants were women with unilateral BC and a strong family history of the disease, including BRCA1 and BRCA2 mutation carriers. Data were collected by interview, self-administered questionnaire, and review of pathology and surgical reports. Associations between having CRRM and potential predictors were assessed using multivariate logistic regression. Results: Of 1018 study participants (median follow-up 5.5 years), 154 (15%) underwent CRRM. The median time from initial BC to CRRM was 1 year. More likely to undergo CRRM were women who were younger at the time of their BC diagnosis (odds ratio [OR] = 0.94 per year of age, p < 0.001), those diagnosed more recently (OR = 1.16 per calendar year, p < 0.001), those who underwent mastectomy rather than breast conservation as their initial definitive BC treatment (OR = 5.2, p < 0.001) and those who underwent risk-reducing salpingo-oophorectomy (OR = 3.4, p < 0.001). BRCA1/2 mutation status and tumor characteristics were not independently associated with CRRM uptake. A contralateral BC event occurred in 177 (20.5%) of the 864 women who did not have CRRM, compared with one chest wall event (0.6%) in the 154 women post-CRRM. Conclusions: Younger women with more recently diagnosed BC treated with mastectomy were most likely to elect CRRM. BRCA1/2 mutation status and the competing risk of BC recurrence and death did not appear to influence decision making.

No significant financial relationships to disclose.