Rethinking breast cancer surveillance in women with BRCA-associated ovarian cancer in the post-solo trial era.

Abstract

5565 Background: Patients with BRCA mutations are at increased risk of developing both breast (BC) and epithelial ovarian cancer (EOC). Optimal breast cancer surveillance guidelines for BRCA mutation carriers following EOC has not been defined due to high risk of EOC recurrence. The recent SOLO-1 trial demonstrated a survival benefit of olaparib maintenance therapy for newly diagnosed women with advanced stage EOC. Olaparib reduced the risk of disease-progression or death by 70% compared to placebo with a median progression-free survival (PFS) of 36 months. Methods: An IRB-approved, multi-institutional study retrospective chart review was performed. Patients had BRCA-associated EOC diagnosed between 1990-2015 without a history of prior BC or mastectomy. All women received combination chemotherapy for EOC. The observed breast cancer free survival was adjusted to reflect the enhanced 3-year PFS observed in olaparib-treated women from the SOLO-1 trial. Kaplan-Meier survival curves were performed. Results: 191 patients with BRCA-associated EOC were included (135 BRCA1, 55 BRCA2, 1 BRCA1 and BRCA2). Median age was 53 years. Most women had advanced stage, high-grade serous EOC (75%). The median overall survival was 7.7 years for BRCA 1, and 9.7 years for BRCA2 mutation carriers. Annual mammography and MRI were performed in 43% and 34% of women, respectively, with a median of 4 mammograms and 3 MRI per patient. 16 women (8.3%) were diagnosed with BC over a median follow up of 80 months: 7 (44%) DCIS and 9 (56%) invasive ductal carcinoma. 14 (88%) women had early stage (0-2) BC. 28 (15%) of women had risk-reducing mastectomy performed an average of 2.1 years following their EOC diagnosis. The incidence of BC increased from 5.6% to 11% at 5- and 10-years post EOC, and in the predicted model with olaparib, from 10% to 17% at 5- and 10-years, assuming olaparib does not impact breast cancer incidence. Conclusions: The risk of metachronous BC following BRCA-associated EOC increases over time. In the post SOLO trial era, BC surveillance strategies in women with EOC should be optimized to reflect improved outcome. [Table: see text]