BMI1 and metastatic malignant neoplasm in the lymph nodes: Multivariate Cox proportional hazards model analysis, which included gender, age, tumor size, histology, T classification, lymph node metastasis, distant metastasis, clinical stage, and the expression of Mel-18, BMI1, phospho-AKT and p16 proteins, showed that BMI1 protein expression, and clinical stage were independent prognostic indicators of overall survival, while Mel-18 was not the independent prognostic indicator.