ESR1 and metastatic malignant neoplasm in the lymph nodes: In univariate analysis, histological grade (P < 0.001), TNM stage (P < 0.001), ER status (P = 0.033), PR status (P = 0.001), and lymph node metastasis (P < 0.001) were also significantly correlated with the 5-DFS of BC patients.