Objective To ascertain the usefulness of CEA determination and cytology of peritoneal washings in the prediction of metastasis of gastric cancer to the peritoneum.Methods CEA was detected at mRNA level by RT PCR and at protein level by radioimmunoassay (RIA). Cytologic examination was done by conventional method. Peritoneal washings were collected during operation from 43 patients with gastric carcinoma and 10 with benign lesions.Results The positive rate of RT PCR was 56.3% and that of RIA was 38.1%. ...