ESR1 and breast cancer: In terms of breast cancer clinical features, high-grade histology increased the odds of a GPV in B1B2P2 by 68% (OR, 1.68; 95% CI, 1.05-2.70), and compared with ER-positive, ERBB2-negative breast cancers, TNBC was associated with a 3-fold increase in the odds of a GPV in B1B2P2 (OR, 3.19; 95% CI, 1.20-8.43).