Value of adjuvant chemotherapy and informed microscopic examination for occult gynecologic cancer detected upon risk-reducing salpingo-oophorectomy after chemotherapy for BRCA1/2-associated breast cancer: a case report.

BRCA1/2 mutation carriers are at high risk for type II ovarian, fallopian tube or peritoneal cancer. Although risk-reducing salpingo-oophorectomy plays an important role in the prevention of these BRCA1/2-associated gynecological cancers, occult ovarian, fallopian tube, or peritoneal cancer is discovered upon risk-reducing salpingo-oophorectomy in 1-4% of BRCA1/2 mutation carriers. Notably, around 30% of BRCA1/2 mutation carriers who undergo risk-reducing salpingo-oophorectomy have undergone adjuvant chemotherapy for breast cancer. We describe the discovery and treatment of occult cancer at the edge of the left fimbria in a BRCA1 mutation carrier who had, just a short time previously, undergone neoadjuvant paclitaxel plus carboplatin (TC) chemotherapy for triple-negative breast cancer. During subsequent risk-reducing salpingo-oophorectomy, a 5.5-mm nodule was observed at the edge of the left fimbria. Microscopic examination of the tumour tissue revealed high-grade serous carcinoma with degenerate tumour cells and fibrosis. Peritoneal fluid was negative for cancer cells. Two months later, hysterectomy, omentectomy and retroperitoneal lymphadenectomy were performed. The final diagnosis was stage FIGO IA fallopian tube cancer. Adjuvant chemotherapy (TC administered every 3 weeks) was applied, and there has been no evidence of recurrence for 5 years. In applying gynecologic surgery and adjuvant chemotherapy, we followed the general recommendation for stage IA fallopian tube cancer. There is no standard strategy for the treatment of occult fallopian tube cancer detected after chemotherapy for BRCA1-associated triple-negative breast cancer. According to our experience in this case, we believe the clinical value of staging laparotomy in cases of a small occult BRCA1/2-associated gynecological cancer should be further investigated.