Expression and clinical significance of melanoma antigen-encoding gene A1 protein in esophageal squamous cell carcinoma

Objective To investigate the expression of melanoma antigen-encoding gene (MAGE) A1 protein in esophageal squamous cell carcinoma, and explore its correlation with the clinicopathological factors and prognosis. Methods A retrospective analysis was performed on 197 patients with esophageal squamous cell carcinoma who accepted radical surgical treatment from January 2006 to December 2012. The expressions of MAGEA1 protein in these specimens of cancer tissue and cancer adjacent tissue were detected by immunohistochemistry with tissue microarray technology. Results MAGEA1 protein was expressed in cytoplasm and nucleus of tumor cells. The positive expression rate of MAGEA1 protein in cancer tissue was significantly higher than that in cancer adjacent tissue: 73.6% (145/197) vs. 5.6% (11/197), and there was statistical difference (P 0.05). Kaplan-Meier survival analysis result showed that the 5-year survival rate in patients with MAGEA1 protein positive expression was significantly lower than that in patients with MAGEA1 protein negative expression (37.2% vs. 53.8%), and there was statistical difference (P = 0.018). Multivariate analysis result showed that MAGEA1 protein positive expression was an independent predictor of prognosis in esophageal squamous cell carcinoma patients (HR = 1.91, 95% CI 1.22 to 2.98, P = 0.004). Conclusions The expression of MAGEA1 protein is abundant in esophageal squamous cell carcinoma, and is related to worse clinical outcome. MAGEA1 protein could be a candidate target for tumor immunotherapy. Key words: Esophageal neoplasms; Prognosis; Melanoma antigen-encoding gene A1 protein; Cancer-testis antigen