Primary ER high-expression was associated with better OS (hazard ratio [HR] = 0.11, 95% confidence interval [CI] 0.02–0.57, P = 0.009) and PR-OS (HR = 0.18, 95% CI 0.05–0.74, P = 0.017) in recurrent BC patients. The gene discussed is ESR1; the disease is breast cancer.