ESR1 and metastatic malignant neoplasm in the lymph nodes: Additionally, the levels of CA15-3, CA125, CEA, and TSGF in nipple discharge were significantly higher than those in serum, and these levels showed a positive correlation with the Ki-67 index, tumor grade, clinical stage, lymph node metastasis, and tumor recurrence and a negative correlation with the level of ER and PR expression.