Correlation between overexpression of c-met gene and the progression of gastric cancer.

The c-met oncogene encodes a receptor of hepatocyte growth factor (HGF), which has both mitogenic and motogenic activities. We have studied the c-met gene expression in gastric cancer by immunohistochemical method using an antibody specific to the c-met beta-chain. c-met immunoreactivity was preferentially localize on the cell membrane, and 55 (43%) of 127 primary gastric cancers showed c-met immunoreactivity. Strong correlation was found between c-met expression in large tumors, lymph node involvement, serosal invasion, as well as peritoneal dissemination. Furthermore, c-met positive tumors had a tendency to metastasize to more distant lymph node sites. Regarding the macroscopic type, Borrmann type 4 gastric cancer showed the highest incidence (12/16, 76%) of positive c-met expression. Patients with c-met positive tumor ran a significantly poorer prognosis than those with c-met negative one. These results indicate that the c-met protein participates in the progression and invasion of stomach cancer, and that c-met tissue status is a useful biological marker in gastric cancer.