Breast cancer surveillance for epithelial ovarian cancer patients with BRCA1 and BRCA2 pathogenic variants: a single-center retrospective study.

Objectives: To identify a method for breast cancer (BC) surveillance in patients with epithelial ovarian cancer (EOC) with germline BRCA1/2 pathogenic variants (gBRCA1/2m) and the incidence of BC after EOC in the era of broad PARP inhibitors use.

Methods: We retrospectively analyzed the data on EOC patients who had gBRCA1/2m by genetic testing between January 2017 and August 2023 in our single center.

Results: Of 125 patients with EOC, 33 had gBRCA1/2m. Of these, 27 (81.8%) underwent BC surveillance, 20 ultrasound and/or mammography, and seven magnetic resonance imaging (MRI). The median time from EOC diagnosis to the initiation of BC surveillance was 8 months. EOC recurrence was significantly lower in the group with MRI than in the group without MRI (no case vs. 10 cases, P = .0261). The duration from EOC diagnosis to the start of BC surveillance was longer in the group with MRI than in the group without MRI (21 vs. 7 months, P = .1033). Two (6.1%) patients developed BC after EOC. Both cases were early stage, triple-negative BCs that occurred more than 3 years after the diagnosis of stage III EOC.

Conclusions: With the advent of PARP inhibitors, long-term survival is expected to increase, and a certain number of patients with EOC after initial treatment may benefit from BC surveillance using MRI. In particular, BC surveillance with MRI may be considered for patients who have not experienced EOC recurrence for more than 2 years.