ESR1 and breast cancer: Compared to the first quartile, the third quartile of MEOHP presented the lowest breast cancer recurrence risk in ER-positive status (aHR 0.18, 95% CI 0.05–0.66, p-value = 0.009), PR-negative status (aHR 0.14, 95% CI 0.03–0.63, p-value = 0.011), and HER2-negative status (aHR 0.24, 95% CI 0.08–0.76, p-value = 0.015).