Salpingo-Oophorectomy Reduces BRCA Mutation Breast Cancer Risk

Author: By Lynda Williams, Senior medwireNews Reporter 

medwireNews: Risk-reducing salpingo-oophorectomy (RRSO) in patients carrying a pathogenic BRCA mutation may help protect against breast cancer for at least 5 years after surgery, indicates research published in JAMA Oncology. 

“[O]ur findings may have important clinical implications for the treatment of women with BRCA1 or BRCA2 pathogenic variants”, say Laurent Briollais, from the Lunenfeld-Tanenbaum Research Institute in Toronto, Ontario, Canada, and co-authors. 

They explain: “Although the primary indication for RRSO is the prevention of ovarian cancer, it is also critical to assess its association with breast cancer risk in order to guide clinical decision-making about RRSO use and its timing.” 

The team collated information from the Breast Cancer Family Registry for 498 families with a BRCA1 mutation and 378 families with a BRCA2 mutation who participated in the case series between 1996 and 2000.  

The BRCA1-affected families included 2650 individuals, of whom 924 had breast cancer. The average age at the time of index breast or ovarian cancer or death in this group was 55.8 years. The BRCA2-affected families included 1925 individuals, of whom 715 had breast cancer. The average age at first event in this group was 57.0 years. 

The average age at time of RRSO in the two cohorts was 44.5 and 46.9 years, respectively, with corresponding ages at the time of first breast cancer diagnosis of 44.2 and 47.9 years. 

Patients who underwent RRSO had a significant reduction in the risk of breast cancer within 5 years of their surgery compared with no RRSO, with hazard ratios (HRs) of 0.28 for BRCA1 carriers and 0.19 for BRCA2 carriers. 

However, the breast cancer risk reduction associated with RRSO was “weaker” after more than 5 years of follow-up, with a significant HR of 0.64 for BRCA1 carriers but a nonsignificant HR of 0.99 for BRCA2 carriers, say Laurent Briollais et al.  

For BRCA1 carriers, the estimated cause-specific cumulative risk of breast cancer by age 70 years was calculated to be 48.2% with RRSO at age 30 years, increasing to 49.7% with RRSO at age 40 years and 52.8% with RRSO at age 50 years versus 61.0% without RRSO. 

For BRCA2 carriers, the cumulative risk of breast cancer by age 70 years with RRSO performed at age 30, 40 or 50 years was 53.5%, 52.7% and 51.7%, respectively, versus 54.0% without RRSO. 

“Therefore, the age at RRSO did not appear to be associated with [breast cancer] cumulative risk among BRCA2 pathogenic variant carriers”, say the investigators.  

They postulate that the difference in breast cancer risk after RRSO between the two mutations “could reflect the different natural histories of the 2 types of breast cancers with earlier age at onset in BRCA1 vs BRCA2 tumors”. 

The authors conclude: “Large cohorts of BRCA1 or BRCA2 pathogenic variant carriers are warranted to better assess the time-varying association of RRSO on [breast cancer].” 

Reference 

Choi Y-H, Terry MB, Daly MB, et al. Association of risk-reducing salpingo-oophorectomy with breast cancer risk in women with BRCA1 and BRCA2 pathogenic variants. JAMA Oncol; Advance online publication 25 February 2021. doi:10.1001/jamaoncol.2020.7995