ESR1 and neoplasm: Variables associated with low pathological complete response rates were tumor grades 1-2 (OR=0.55; 95% CI=0.37-0.81; p=0.03), estrogen receptor positivity (OR=0.65; 95% CI=0.43-0.97; p=0.04), and progesterone receptor positivity (OR=0.44; 95% CI=0.29-0.65; p=0.0001).