ESR1 and neoplasm: [T3 vs.T1] •Among all postmenopausal women: RR = 1.21 (1.07–1.36) for all invasive tumors; RR = 1.19 (1.03–1.36) for ER+ tumor; RR = 1.33 (0.95–1.87) for ER- tumors;•Among lean and normal weight (BMI, 18.5-25 kg/m2): RR = 1.25 (1.05–1.49) for all invasive tumors; RR = 1.25 (1.03–1.52) for ER+ tumors; RR = 1.22 (0.76–1.93) for ER-tumors