[Evaluation of sialylated LewisX as a tumor-associated carbohydrate antigen in the sera of patients with gastric cancer].

The clinical usefulness as a tumor-associated antigen of the new monoclonal antibody CSLEX1, which reacts with the sialylated LewisX antigen, has been evaluated serologically in 141 patients with a gastric cancer. The serum sialylated LewisX was measured by fluorescent EIA. The percent positive figure of these gastric cancer patients was 17.0% (24/141), which indicates a significant increase when compared with that of the controls. The percent-positive values, according to the clinical stage, were 9.2%, 9.1%, 15.6%, and 36.4% for stages I, II, III, and IV, respectively. The degree of liver metastasis and peritoneal dissemination of the cancer correlated with the percent-positive values of the antigen. This suggests that sialylated LewisX is useful as a tumor-associated antigen.