In a UK study reported in the Journal of Clinical Oncology, Gandhi et al found that whereas breast cancer incidence was reduced with bilateral risk–reducing mastectomy (BRRM) among women carrying BRCA1/BRCA2 pathogenic variants, no difference vs surveillance was observed in breast cancer–specific or overall survival.
Study Details
In the study, 1,205 women attending a regional family history/genetics service who had been found to carry pathogenic variants of BRCA1 and BRCA2 genes (pvBRCA1/2) elected to undergo BRRM (n = 460, median age = 37.2 years) or surveillance (n = 745, median age = 38.5 years). A greater proportion of the surveillance group was older than 60 years at testing (11.4% vs 2.3%, P < .000).
Key Findings
Follow-up for cancer incidence in the whole cohort was 4,652.9 woman-years. The annual breast cancer incidence rate among all women in the study was 2.4%; in the BRRM group, it was 0.15%, representing a 94% reduction compared with surveillance (P < .001). Nine occult cancers were diagnosed at BRRM.
After 4,634 vs 5,419 woman-years of follow-up, breast cancer–specific death occurred in two patients in the BRRM group vs four in the surveillance group (P = .36). No differences in overall survival were observed for 10-year age groups, except for the 50- to 59-year group; in this age group, one death due to breast cancer was observed in the surveillance group.
The investigators concluded: “For women electing imaging surveillance over risk-reducing surgery, our results may offer reassurance that their breast cancer–specific survival and [overall survival] are unlikely to be compromised. 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.”
Ashu Gandhi, MD, of Division of Cancer Sciences, University of Manchester, Manchester, UK, is the corresponding author for the Journal of Clinical Oncology article.
DISCLOSURE: The study was supported by grants awarded to the Manchester Biomedical Research Centre by the National Institute for Health Research. For full disclosures of the study authors, visit ascopubs.org.
