Thymosin beta-4 overexpression correlates with high-risk groups in gastric gastrointestinal stromal tumors: A retrospective analysis by immunohistochemistry.

BACKGROUND: Thymosin beta-4 (Tβ4) is a protein that is linked to a number of important biological actions and recently tumor progression and poor prognosis of some tumors. The aim of this study was to evaluate Tβ4 expression in gastric GISTs and correlate with some clinicopathological characteristics related with prognosis and clinical outcome in order to add further data to the current literature. METHODS: Tβ4 antibody was applied to the 4μm-thick paraffin sections of 57 gastric GISTs by immunohistochemistry. RESULTS: Tβ4 expression was found to be directly corrrelated with higher risk groups, tumor size, mitotic count, cellularity, and necrosis while it was inversely correlated with overall survival (OS) by univariate analysis (p=0.000, p=0.001, p=0.000, p=0.025, p=0.023, and p=0.042, respectively). The direct association between Tβ4 expression and risk groups were also supported by multivariate analysis (p=0.000, β=0.497, t=4.374). CONCLUSION: Overexpression of Tβ4 was found to be related with predictive characteristics for tumor progression and adverse prognosis. Thus, we suggest that overexpression of Tβ4 might play a role in the progression of gastric GISTs and might be used as a potential prognostic tool as well as a target for novel therapies.