After adjusting the traditional prognostic factors (age, tumor size, lymph node involvement, stage, ER/PR status, HER2 status, and LVI), OS/OA combined with tamoxifen reduces significantly the risk of recurrence (HR = 0.41, 95% CI 0.28–0.61, P <0.001) and death (HR = 0.33, 95% CI 0.22–0.50, P <0.001), for patients with normal menses after chemotherapy. The gene discussed is ESR1; the disease is neoplasm.