As shown in Table 4, univariate analysis with a Cox proportional hazards model revealed that OS was associated with the following characteristics: AJCC stage (P = 0.0005), lymph node metastasis (P = 0.0043), recrudescence (P < 0.0001), ER expression (P = 0.0012), P53 expression (P = 0.0232) and NUDT5 expression (P < 0.0001). Here, ESR1 is linked to metastatic malignant neoplasm in the lymph nodes.