Research suggests survival is not impacted by risk-reducing surgery in high-risk women, despite significant reductions in cancer incidence.
Both breast cancer-specific survival and overall survival were not impacted by bilateral risk-reducing mastectomy in women carrying pathogenic variants of BRCA1 and BRCA2 genes, according to UK researchers.
The team at the University of Manchester compared the long-term oncology outcomes of women choosing BRRM with those choosing a program of imaging surveillance as per national guidance.
In the UK, all pvBRCA carriers have had the option of undergoing BRRM and risk-reducing bilateral salpingooophorectomy (RRSO), regardless of whether they’ve been affected by cancer. According to the Australian Prescriber, BRRM is a controversial clinical option for women who are at increased risk.
A total of 460 women elected to undergo BRRM, while 745 chose surveillance (median age 37.2 years and 38.5 years, respectively), for a total follow-up of 4652 woman-years after BRRM. A larger proportion of women with pvBRCA1 chose BRRM than women with pvBRCA2 (44% vs 33%, respectively).
The annual incidence rate for breast cancer in the cohort was 2.4%. Of the 105 women in the surveillance group diagnosed with breast cancer, 51 proceeded with BRRM at time of diagnosis.
Breast cancer mortality was similar between the groups – two deaths per 4634 woman-years in the BRRM group and four deaths per 5419 woman-years in the surveillance group (0.043% vs 0.074%, respectively).
Proportionately, mortality rates between breast cancer and ovarian cancer were similar across both the BRRM and surveillance groups.
Excluding the nine occult breast cancer cases (six in pvBRCA1 and three in pvBRCA2 found at time of surgery), annual breast cancer incidence rate after BRRM dropped to 0.15%, equivalent to a 94% reduction compared with the surveillance group.
Related
Cancer Australia estimated that average cumulative risk of developing breast cancer for women with a BRCA1 mutation by 70 years of age was 57%, increasing to 80% by age 80. For women with a BRCA2 mutation, this was estimated at 49% and 88%, respectively.
Nearly 60% of women with pvBRCA1 and more than a quarter of women with pvBRCA2 are diagnosed with cancer before the age of 50.
“For women electing imaging surveillance over risk-reducing surgery, our results may offer reassurance that their breast cancer–specific survival and OS are unlikely to be compromised,” authors wrote.
“However, breast cancer incidence rates are significantly reduced after BRRM compared with imaging surveillance, which may be important information for women with pvBRCA1/2 considering BRRM.”
