Clinical and pathological outcomes of risk-reducing salpingo-oophorectomy for Japanese women with hereditary breast and ovarian cancer.

BACKGROUND: To clarify the clinical as well as pathological outcomes in Japanese women with germline pathogenic BRCA1/2 variants who underwent risk-reducing salpingo-oophorectomy (RRSO). METHODS: This prospective study examined the rate of occult cancer and primary peritoneal cancer after RRSO at our institution in the period from 2011 to 2020. Clinical records of genetically confirmed patients with germline pathogenic BRCA1/2 variants who desired to undergo RRSO were reviewed. Specimens obtained during RRSO were pathologically diagnosed as per SEE-FIM protocol. All the participants underwent magnetic resonance imaging (MRI) about 1 month preoperatively. RESULTS: One hundred and seventeen women underwent RRSO during this period. Of these, the numbers of women with germline pathogenic BRCA1 and BRCA2 variants were 72 and 45, respectively. The mean observational time after RRSO was 35.8 months. Despite negative preoperative screening results, three (2.6%) serous tubal intraepithelial carcinoma and three (2.6%) invasive carcinomas were identified. Of the three invasive carcinomas cases, two were International Federation of Gynecology and Obstetrics (FIGO) stage I primary fallopian tube cancer, and the third case was double cancer (ovarian cancer and fallopian tube cancer) with FIGO stage IC3. CONCLUSIONS: The rate of occult neoplasms was similar to those reported by studies performed in other countries. Although women with occult cancer were diagnosed with FIGO stage I, the MRI performed 1 month preoperatively did not show any such malignant findings. Thus, RRSO is the only promising method that can improve the prognosis in women with germline pathogenic BRCA1/2 variants.