Serum erbb-2 protein for the diagnosis of gastric-cancer.

A new tumor marker was tested (serum erbB-2 protein) in 128 patients with gastric cancer and 110 patients with benign gastric diseases, and the results were correlated with erbB-2 tissue status and clinicopathological parameters. Abnormal level of erbB-2 protein was found in 15/128 (12%) of gastric cancer patients and in 2/110 (2%) of benign gastric diseases. Elevated erbB-2 levels did not correlate with age, sex, tumor size, macroscopic type, histologic type, serosal invasion, nodal status, or clinical stage. In all the 15 patients except one case, with abnormally high level of serum erbB-2, erbB-2 immunoreactivity was confirmed in the primary tumors by immunohistochemical staining. The percentage of positive serum levels of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and CA 19-9 were 6%, 16% and 20%, respectively. However, there was no relation between serum erbB-2 level and CA 19-9, CEA or AFP level. If the CA 19-9 was assayed in combination with erbB-2, the overall sensitivity was 30%. In addition, the combination of the three markers of erbB-2, CEA and CA 19-9 gave a sensitivity of 41%. Patients with abnormal erbB-2 serum level run poorer prognoses than did the patients with normal erbB-2 serum level. We conclude that erbB-2 protein is an attractive tumor marker, and a powerful prognostic indicator of gastric cancer patients.