STMN-1 gene: a predictor of survival in stage iia esophageal squamous cell carcinoma after Ivor-Lewis esophagectomy?

Abstract

Background: Prognosis of esophageal squamous cell carcinoma (ESCC) is stage-specific; however, some patients with the same stage have different survival outcomes. Clinically, it is significant to explore the biological marker to predict patient's outcome. We investigated the association between the stathmin1 gene (STMN-1) expression and the prognosis of patients who underwent Ivor-Lewis esophagectomy.

Methods: A total of 162 patients who suffered from midthoracic stage IIA ESCC and completely resected with Ivor-Lewis esophagectomy were studied for STMN-1 expression by qRT-PCR in fresh-frozen tissue and validated by immunohistochemistry in matched formalin fixed-paraffin embedded tissue samples. STMN-1 level was evaluated as a prognostic factor in ESCC. SPSS 21.0 software was used to analyze the relationship between STMN-1 expression and clinicopathological characteristics and survival probability.

Results: The overall 3- and 5-year survival was 72.20 and 42.00 % respectively. Ninety-four patients (58.02 %) experienced disease recurrence with a disease-free interval of 21.50 ± 1.20 months. qRT-PCR result showed that STMN-1 mRNA level in patients who were alive at the end of follow-up was lower compared with patients who died during the follow-up period (p < 0.05). Immunohistochemical results showed that 94 patients had STMN-1 protein overexpression (58.02 %), patient with STMN-1 overexpression had worse survival compared with patients who had low STMN-1 expression (p = 0.00). Cox regression analysis revealed that STMN-1 protein expression and T classification are independent prognostic factors.

Conclusions: Even localized ESCC are potential to relapse with poor prognosis. This study demonstrates that STMN-1 level is an independent prognostic factor after Ivor-Lewis esophagectomy. In addition, assessment of STMN-1 level could improve stratification of stage IIA ESCC patients.