Effect of Prior Bilateral Oophorectomy on the Presentation of Breast Cancer in BRCA1 and BRCA2 Mutation Carriers

PURPOSE: To compare the presentation of invasive breast cancer in BRCA1 and BRCA2 mutation carriers with and without prior bilateral oophorectomy. PATIENTS AND METHODS: Women with a BRCA1 or BRCA2 mutation with the diagnosis of invasive breast cancer were identified from ten cancer genetics clinics. The medical history, medical treatment records and pathology reports for the breast cancers were reviewed. Information was abstracted from medical charts, including history (and date) of oophorectomy, date of breast cancer diagnosis, stage of disease, and pathologic characteristics of the breast cancer. Women with prior bilateral oophorectomy were matched by age, year of diagnosis, and mutation with one or more women who had two intact ovaries at the time of breast cancer diagnosis. Characteristics of the breast tumours were compared between the two groups. RESULTS: Women with prior bilateral oophorectomy presented with smaller tumours on average compared to women without prior oophorectomy (mean size 1.50 cm vs. 1.95 cm; p = 0.01). Additionally, although not statistically significant, women with intact ovaries were more likely to have high-grade tumour (70% vs. 54%: p = 0.10) and to have positive lymph nodes (34% vs. 18%; p = 0.11) compared to women with prior bilateral oophorectomy. CONCLUSIONS: Bilateral oophorectomy prior to breast cancer appears to favourably influence the biological presentation of breast cancer in BRCA1 and BRCA2 mutation carriers.