After accounting for age, tumor size, nodal positivity and receipt of adjuvant chemotherapy, pre-menopausal women with ERβ+ disease were more likely to have shorter OS than pre-menopausal women with ERβ− disease (HRadj = 2.06; 95% CI: 1.14–3.71; p = 0.017). This evidence concerns the gene ESR2 and neoplasm.