Breast cancer surveillance following ovarian cancer in BRCA mutation carriers

BRCA 1 or 2 mutation carriers have increased risk of developing breast cancer (BC) and serous epithelial ovarian cancer (EOC). The incidence of BC over time after EOC is unknown. Optimal BC surveillance for BRCA mutation carriers following EOC has not been defined.

A multi-institutional retrospective chart review was performed. Patients with BRCA -associated EOC diagnosed between 1996 and 2016 were followed for an average of 80 months. Women with previous bilateral mastectomy were excluded; women with prior BC and an intact breast were included. Descriptive statistics, Chi Square, and univariate survival analysis were performed.

184 patients with BRCA -associated EOC were identified. Eighteen (10%) were diagnosed with BC a median of 48 months following EOC. Two (1%) with prior BC developed contralateral BC and 16 (9%) developed primary BC. The majority of BC (55%) was diagnosed 3 years following EOC. The 3-, 5- and 10-year incidence of BC was 5.6%, 9.5% and 33.3%. Annual mammography was performed in 43% and MRI in 34%. Twenty-eight (15%) women underwent risk-reducing mastectomy (RRM). There was no statistically significant difference in BC screening between women with, and without, a prior BC. BC was most commonly detected on mammogram. Three (17%) women had occult BC at the time of RRM. Nine (50%) had DCIS, and 8 (44%) had stage I/II BC. Median 5- and 10-year survival was 68% and 43% and was comparable between groups.

Ten percent of women developed BC after EOC. The incidence of BC following EOC in BRCA carriers increases over time, and surveillance is recommended given their enhanced survival of EOC. Timely genetic testing for women with EOC is imperative to better triage BC screening resources and treatment.