Insulin-like Growth Factor II mRNA-Binding Protein 3 Expression in Benign and Premalignant Lesions and Carcinomas of the Stomach

Background: Recent studies have demonstrated that insulin-like growth factor II mRNA-binding protein 3 (IMP3) is expressed in malignant tumors of various organs but not in normal tissue. We investigated IMP3 expression in various benign lesions, premalignant lesions and carcinomas of the stomach. Methods: IMP3 immunohistochemical staining was performed on 24 benign gastric lesions, 24 gastric adenomas, and 322 gastric carcinomas. Results: IMP3 was not expressed in benign gastric lesions including adenomas with low-grade dysplasia, but was expressed in 17% of adenomas with high-grade dysplasia, and in 44% of carcinomas. As the carcinomas were in the advanced stage, they expressed IMP3 more frequently and strongly. Patients with IMP3-positive tumors had poorer survival than those with negative tumors. Conclusions: IMP3 expression in gastric carcinoma may be related to tumor invasion and metastasis, and is an independent risk factor for poor prognosis.