The variables considered in the multivariate analysis for OS and RFS were the age of the patients, tumor stage, tumor depth, lymph node metastasis, distant metastasis, histological grade, tumor necrosis, tumor differentiation, mitotic count, Ki67 index, and the expression of SIRT1, DBC1, P53, β-catenin, and cyclin D1. Here, SIRT1 is linked to metastatic malignant neoplasm in the lymph nodes.