Key clinical point: Contrary to women who received bilateral oophorectomy, women who underwent hysterectomy and concurrent estrogen plus progestin therapy had a significantly higher risk of developing breast cancer (BC).
Major finding: Bilateral oophorectomy (hazard ratio [HR] 0.91; 95% CI 0.83-1.00) did not increase the risk for BC irrespective of the use of hormone therapy. However, hysterectomy alone was positively associated with an increased risk for BC (HR 1.12; 95% CI 1.02-1.23), especially among those receiving estrogen plus progestin therapy (HR 1.25; 95% CI 1.01-1.55).
Study details: Findings are from a prospective cohort study, The Sister Study, including 50,701 women without BC who had a biological sister with BC, of which 13.8% and 18.1% of participants underwent hysterectomy only and bilateral oophorectomy with or without hysterectomy, respectively.
Disclosures: This study was funded by the Intramural Research Program at the US National Institutes of Health and other sources. The authors declared no conflicts of interest.
Source: Lovett SM et al. Hysterectomy, bilateral oophorectomy, and breast cancer risk in a racially diverse prospective cohort study. J Natl Cancer Inst. 2023 (Feb 20). Doi: 10.1093/jnci/djad038