Investigation of the expression of MTA1 protein and its relationship to the prognosis in squamous cell carcinoma of the esophagus after esophagectomy

Abstract

Objective To investigate the expression of MTA1 protein and its relationship to the prognosis in esophageal cancer after esophagectomy. Methods One hundred and sixty-five patients with middle third squamous cell carcinoma of the esophagus were enrolled in this study. All patients underwent operation in Provincial Hospital Affiliated to Shandong University between January 2002 and January 2004. The expression of MTA1 protein was detected by immunohistochemistry. All statistic analyses were performed with SPSS 10.0 statistical software. According to the clinicopathologic factors, the difference of MTA1 protein expression was compared by x2 test. Kaplan-meier method was performed to calculate the survival rate, Cox regression multivariate analysis was performed to determine independent prognostic factors. Results The 5-year survival rate in Ⅰ stage,Ⅱ stage and Ⅲstage was separately 100.0% 、38.3% and 22.4%, and the MTA1 protein expression rate in Ⅰ stage, Ⅱ stage and Ⅲ stage was separately 25.0% 、30.9% and 57.9%, the difference of MTA1 protein expression between Ⅱ stage and Ⅲ stage was statistically significant ( x2 = 11.6, P = 0. 00). The MTA1 protein expression rate in T1 stage, T2 stage and T3 stage was separately 42.9% 、13.3% and 50%. MTA1 protein expression rate in T2 stage patients and T3 stage patients was separately 13.3% and 50%, the difference of MTA1 protein expression between them was statistically significant (x2 = 13.2, P =0.00). The positive expression of MTA1 protein in patients with lymph node metastasis was significantly higher than those without metastasis ( x2 = 8.2, P = 0.04). The 5-year survival rate in patients with MTA1 protein positive expression was significantly lower than those without MTA1 protein positive expression (P =0.00 ), and the 5-year survival rate in T3 stage patients with MTA1 protein positive expression was significantly lower than those without MTA1 protein positive expression ( P =0.01 ), and the 5-year survival rate in N0 stage patients with MTA1 protein positive expression was significantly lower than those without MTA1 protein positive expression (P = 0.03 ), and the 5-year survival rate in N1 stage patients with MTA1 protein positive expression was significantly lower than those without MTA1 protein positive expression ( P =0.04). However, the 5-year survival rate in T2 stage patients with MTA1 protein positive expression was not significantly lower than those without MTA1 protein positive expression (P =0.20). The result of Cox analysis demonstrated that N stage and MTA1 protein positive expression were independent prognostic factors. Conclusion MTA1 protein overexpression was detected in esophageal squamous cell carcinoma and was found to be significantly associated with T stage and lymph node metastasis. The patients with MTA1 protein overexpression was significantly lower the 5-year survival rate than without MTA1 protein expression. Lymph node metastasis and MTA1 protein overexpression were independent prognostic factors. Key words: Esophageal neoplasms; Lymphatic metastasis; Thoracic surgical procedures; Neoplasm metastasis