Preventing breast and ovarian cancers in high-risk BRCA1 and BRCA2 mutation carriers.

OBJECTIVE: To estimate the prevalence of the use of cancer risk-reducing measures among Australian BRCA1 and BRCA2 mutation carriers.

DESIGN, SETTING AND PARTICIPANTS: Prospective follow-up of female carriers of BRCA1 or BRCA2 mutations who had no personal history of cancer and were enrolled in a multiple-case breast cancer family cohort study (kConFab). Data, including cancer events and uptake of risk-reducing surgery and medication were collected by self-report at cohort entry and 3 yearly thereafter. Surgery was confirmed from pathology and medical records. Women were followed up from enrolment until cancer diagnosis, date of last follow-up, or death. Data were collected from 3 November 1997 to 21 May 2012.

MAIN OUTCOME MEASURES: Uptake of risk-reducing surgery and/or medication.

RESULTS: Of 175 BRCA1 and 150 BRCA2 mutation carriers (median age, 37 years at cohort enrolment), 69 (21%) underwent risk-reducing mastectomy, 125 (38%) underwent risk-reducing bilateral salpingo-oophorectomy and nine (3%) participated in a clinical trial of risk-reducing medication, during 2447 person-years of follow-up (median follow-up, 9 years). Sixty-eight women (21%) reported incident cancers, including 52 breast cancers and nine ovarian cancers (defined in this article as high-grade serous cancers of the ovary, fallopian tube or peritoneum).

CONCLUSIONS: There is considerable scope to increase the uptake of cancer risk-reducing measures in Australian BRCA1 and BRCA2 mutation carriers. These findings should drive (i) future research into the factors contributing to low uptake in Australia and (ii) changes to policy and practice to help better translate genetic knowledge into reductions in cancer incidence.