ESR1 and neoplasm: In multivariate analysis, including the prognostic factors age, nodal status, differentiation grade, tumor size, ER status, and adjuvant therapy, the association was independent: Δχ2 = 10.0 (df = 3), P = 0.018; HR = 2.14, 95% CI 1.32 to 3.45, P = 0.002.