IMP3 expression in gastric cancer: association with clinicopathological features and HER2 status.

Background: The aim of this study was to evaluate the expression of IMP3, an independent poor prognostic factor for many cancers, and its association with clinicopathological features and HER2 status.
Methods: Gastrectomy specimens from 106 patients were evaluated by immunohistochemistry and fluorescence in situ hybridization.
Results: HER2 overexpression was found in 4.71 % of the samples. A negative association was observed between HER2 overexpression and grade of differentiation. No association was observed between HER2 overexpression and status of surgical margins, vascular invasion, perineural invasion, nodal metastasis and depth of invasion. Among all specimens of gastric cancer, 67.92 % were positive for IMP3. Expression of IMP3 was significantly higher in specimens with vascular invasion, perineural invasion, nodal metastasis and higher depth of invasion. HER2 overexpression was detected in only 5.55 % of IMP3 positive specimens.
Conclusions: IMP3 expression was frequently observed in gastric cancer and was associated with poor prognostic clinicopathological features. A survival benefit with HER2 therapy should be expected for the minority of patients with IMP3 positive specimens. Studies should be conducted to evaluate the response to HER2 therapy of gastric cancer expressing IMP3.