ESR1 and metastatic malignant neoplasm in the lymph nodes: Estrogen receptor (ER) and progesterone receptor (PR) status were categorized as positive or negative; tumor grade as 1, 2 or 3; stage as I, II and III/IV; Her2 status as positive or negative; Presence of lymph node metastases at diagnosis (LN) as yes or no; and family history as positive or negative.