Using univariate survival analysis, the clinical TNM stage (P=0.010), menopause (P=0.020), miR-320a expression level (P=0.015) and distant metastasis (P=0.001) were found to be significantly associated with prognosis, however, no significant differences were identified between prognosis and age (P=0.587), lymph node metastasis (P=0.076), chemotherapy (P=0.900), tumor size (P=0.230), histological grade (P=0.977), ER expression (P=0.802), PR expression (P=0.445) or HER-2 expression (P=0.650) (Table III). The gene discussed is ESR1; the disease is metastatic malignant neoplasm in the lymph nodes.