Abstract

A soluble fragment of the c-erbB-2 oncoprotein become detectable in the serum of the breast cancer petients by enzyme-linked immunosorbent assay(ELISA). To evaluate the clinical sig- nificance of soluble c-erbB-2 in gastric cancer, we measured the serum levels in 45 normal healthy persons and in 86 gastric cancer patients. Fifty-five patients were underwent surgery(47 curative surgery, 8 palliative surgery) and thirty-one patients were inoperable(18 advanced, 8 relapsed, 6 progressed after palliative surgery). The c-erbB-2 serum levels were below 14 U/ml in normal persons. Three of 86(3.5%) sam- ples from gastric cancer patients had elevated serum c-erbB-2 leveL In 55 operated patients, all serum samples were negative for c-erbB-2. Elevated serum levels were predominantly found in patients with initially advanced cancers(3/18: 16.7%). In 22 operated cases, immunohisto- chemical staining showed 36.4% c-erbB-2 positive ratio(8/22) in tissues. Comparing the results from sera and tissues studies, the sensitivity of serum ELISA assay was too low even if the specificity was high. Our data suggest that the soluble c-erbB-2 oncoprotein can be a tumor marker only in advanced stage of gastric cancer. Further studies are warrented to elucidate the discrepancy between the serum and tissue results in oprable early stage gastric cancer.

• Keywords: Gastric cancer, Serum c-erbB-2, ELISA