SERUM ERBB-2 PROTEIN FOR THE DIAGNOSIS OF GASTRIC-CANCER

A new tumor marker was tested (serum erbB-2 protein) in 128 patients w ith gastric cancer and 110 patients with benign gastric diseases, and the results were correlated with erbB-2 tissue status and clinicopatho logical parameters. Abnormal level of erbB-2 protein was found in 15/1 28 (12%) of gastric cancer patients and in 2/110 (2%) of benign gastri c diseases. Elevated erbB-2 levels did not correlate with age, sex, tu mor size, macroscopic type, histologic type, serosal invasion, nodal s tatus, or clinical stage. In all the 15 patients except one case, with abnormally high level of serum erbB-2, erbB-2 immunoreactivity was co nfirmed in the primary tumors by immunohistochemical staining. The per centage of positive serum levels of alpha-fetoprotein (AFP), carcinoem bryonic 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 t he 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 d id the patients with normal erbB-2 serum level. We conclude that erbB- 2 protein is an attractive tumor marker, and a powerful prognostic ind icator of gastric cancer patients.