c-Met Expression in Colorectal Carcinoma and Adenomas: Correlation with Clinicopathologic Parameters

ABSTRACT

PURPOSE: Hepatocyte growth factor (HGF) stimulates proliferation, migration, and morphogenesis of epithelial cells by specifically binding to its receptor c-met. Abnomalities of the c-met oncogene have been studied in cancers of many organs including thyroid, lung, pancreas, and stomach. However, little is known about the clinical significance of c-met oncogene abnormalities in colorectal carcinomas. In this study, we investigated over- expression of the c-met protein in colorectal adenomas and adenocarcinomas, and analyzed the clinicopathologic significance of this over-expression. METHODS: Expression of the c-met protein localized in colorectal adenoma and adenocarcinoma tissues was analyzed by using immunohistochemistry. The results were compared with clinicopathologic parameters to find clinical correlation. RESULTS: c-met protein was detected in 42.5% (17/40) of colorectal cancers and in 10.0% (4/40) of colorectal adenomas (P= 0.001). In colorectal cancer, the proportion of expression of c-met protein was 0% (0/40) in stage I, 47.6% (10/40) in stage II, 53.8% (7/40) in stage III and, 0% (0/40) in stage IV. c-met protein expression was 18.8% (3/40) in tumors with invasion into the muscularis propria (MP), and 58.3% (14/40) in tumors with invasion beyond the MP. The depth of tumor invasion was a statistically significant factor (P=0.022) for c-met expression. CONCLUSIONS: The c-met protein expression was related to the depth of invasion of colorectal cancer and showed a significant difference in its rate of expression between adenoma and adenocarcinomas.