The prognostic significance of ING4 expression on gastric gastrointestinal stromal tumors by immunohistochemistry

Abstract

OBJECTIVE: Inhibitor of growth 4 (ING4) is a novel tumor suppressor gene that is reported to be down-regulated in various tumors including gastrointestinal stromal tumors (GISTs) originated from different locations, recently. Herein, we aimed to evaluate ING4 expression and its prognostic significance on gastric GISTs in order to add further data to the current literature.

MATERIAL AND METHODS: ING4 was evaluated in samples of gastric GISTs from 62 patients, by immunohistochemistry. The association between ING4 expression and clinicopathological features related with prognosis and overall survival (OS) were analyzed statistically.

RESULTS: There was statistically significant inverse correlation between ING4 expression and risk groups according to both NIH and AFIP, Ki67 index, tumor diameter, and mitotic count by univarite analysis (p=0.000, p=0.000, p=0.08, p=0.01, and p=0.028, respectively). The negative association between ING4 expression and risk groups according to both NIH (p=0.002, β=-0.263, t=-3.166) and AFIP (p=0.016, β=-0.244, t=-2.492) was supported by multivariate analysis. There was statistically significant direct correlation between low levels of ING4 expression and shorter OS by univariate (p=0.000) and multivariate analysis (p=0.000, β=0.769, t=9.798), as well as Kaplan-Meier method (p=0.035).

CONCLUSIONS: The low ING4 expression level was found to be related with unfavorable prognosis. Thus, we suggest that loss of ING4 expression might play a role in the progression of GISTs and might be used as a potential prognostic tool. Additionally, this is the first study that has evaluated the association of ING4 expression on gastric GISTs, to the best of our knowledge. Therefore, we claim that more comprehensive future studies including higher number of patients and longer follow-up might clarify the potential role of ING4 on pathogenesis and prognosis of GISTs.