Sirtuin 2 (Sirt2) Expression Predicts Lymph Node Metastasis and Poor Overall Survival of Patients with Esophageal Squamous Cell Carcinoma

Background: Altered expression of Sirtuin 2 (Sirt2) was associated with cancer development and progression. This study further assessed the association of Sirt2 expression with clinicopathological data and prognosis of patients with esophageal squamous cell carcinoma (ESCC) after postoperative concurrent chemoradiotherapy. Methods: Tissue specimens from 95 ESCC patients were collected for immunohistochemical analysis of Sirt2 expression, which was used to determine association with patient clinicopathological and survival data. Results: Sirt2 protein was expressed in 53.7% of ESCC tissue specimens but only in 25.3% of normal squamous epithelium (p = 0.000). Sirt2 expression was associated with tumor invasion (p = 0.005), lymph node metastasis (p = 0.003), and advanced clinical stage (p = 0.000), but not with tumor size (p = 0.199), or differentiation (p = 0.177). Sirt2 expression was associated with poor overall and progression-free survival (p = 0.034). The multivariate analysis showed that Sirt2 expression was an independent predictor for overall survival of patients with resected ESCC followed by concurrent chemoradiotherapy (p = 0.048). Conclusions: Sirt2 protein expression in ESCC tissue specimens was associated with ESCC invasion, lymph node metastasis, and advanced tumor clinical stage, as well as poor overall and poor progression-free survival. Sirt2 expression is an independent prognostic predictor for ESCC patients.