Pregnancy After Breast Cancer in Patients With Germline <i>BRCA</i> Mutations.

Abstract

Young women with germline <i>BRCA</i> mutations have unique reproductive challenges. Pregnancy after breast cancer does not increase the risk of recurrence; however, very limited data are available in patients with <i>BRCA</i> mutations. This study investigated the impact of pregnancy on breast cancer outcomes in patients with germline <i>BRCA</i> mutations. This is an international, multicenter, hospital-based, retrospective cohort study. Eligible patients were diagnosed between January 2000 and December 2012 with invasive early breast cancer at age ≤ 40 years and harbored deleterious germline <i>BRCA</i> mutations. Primary end points were pregnancy rate, and disease-free survival (DFS) between patients with and without a pregnancy after breast cancer. Pregnancy outcomes and overall survival (OS) were secondary end points. Survival analyses were adjusted for guarantee-time bias controlling for known prognostic factors. Of 1,252 patients with germline <i>BRCA</i> mutations (<i>BRCA1</i>, 811 patients; <i>BRCA2</i>, 430 patients; <i>BRCA1/2</i>, 11 patients) included, 195 had at least 1 pregnancy after breast cancer (pregnancy rate at 10 years, 19%; 95% CI, 17% to 22%). Induced abortions and miscarriages occurred in 16 (8.2%) and 20 (10.3%) patients, respectively. Among the 150 patients who gave birth (76.9%; 170 babies), pregnancy complications and congenital anomalies occurred in 13 (11.6%) and 2 (1.8%) cases, respectively. Median follow-up from breast cancer diagnosis was 8.3 years. No differences in DFS (adjusted hazard ratio [HR], 0.87; 95% CI, 0.61 to 1.23; <i>P</i> = .41) or OS (adjusted HR, 0.88; 95% CI, 0.50 to 1.56; <i>P</i> = .66) were observed between the pregnancy and nonpregnancy cohorts. Pregnancy after breast cancer in patients with germline <i>BRCA</i> mutations is safe without apparent worsening of maternal prognosis and is associated with favorable fetal outcomes. These results provide reassurance to patients with <i>BRCA</i>-mutated breast cancer interested in future fertility.