Multinational retrospective cohort study of feasibility and safety of pregnancy after breast cancer in women with germline BRCA1/2 pathogenic variants

Young women with breast cancer who have germline pathogenic variants (PVs) in BRCA1 or BRCA2 face unique challenges regarding fertility. A multinational retrospective cohort study, including 4732 BRCA1/2 PV carriers with a diagnosis of breast cancer before age 41 years between 2000 and 2021, found that 659 patients had at least one pregnancy after breast cancer, for a cumulative pregnancy incidence of 22% at 10 years. Pregnancy following breast cancer was not associated with adverse neonatal outcomes. During median 7.8 years of follow-up, the disease-free survival was not significantly different between the group with versus the group without pregnancy (aHR 0,99; 95% CI 0.81-1.20) while breast cancer-specific survival (0.53; 0.37-0.74) and overall survival (0.52; 0.38-0.72) were significantly better in the group with versus the group without pregnancy. The authors conclude that pregnancy after breast cancer in BRCA1/2 pathogenic variant carriers was feasible and safe.