Multivariable analyses showed that BRCA1 variant carriers treated with BCT had similar survival compared with those treated with mastectomy with radiotherapy (BCSS: hazard ratio [HR], 0.58 [95% CI, 0.16-2.10]; P = .41; OS: HR, 0.61 [95% CI, 0.18-2.12]; P = .44) or mastectomy alone (BCSS: HR, 0.70 [95% CI, 0.22-2.20]; P = .54; OS: HR, 0.77 [95% CI, 0.27-2.21]; P = .63) after adjusting for age at diagnosis, family history of breast and ovarian cancer, year of diagnosis, tumor size, tumor grade, lymph node, estrogen receptor, progesterone receptor, ERBB2, and adjuvant therapy (Table 2). Here, ESR1 is linked to ovarian cancer.