ESR1 and metastatic malignant neoplasm in the lymph nodes: Large tumor size (pT2-4), presence of lymph node metastasis (pN1-3), lack of expression of hormonal receptors (ER and PR), and triple-negative molecular subtype were significant predictors of poor prognosis, i.e. short DFS in the set of chemotherapy-treated patients (p<0.001, p = 0.001, p = 0.011, p = 0.001, and p = 0.003, respectively).