[The value of CEA mRNA, CEA protein and cytology of peritoneal washings in the prediction of metastasis of gastric cancer].

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%. Both were more sensitive than that of cytologic examination (33.1%) of free cancer cells in the peritoneal washings. The level of CEA mRNA expression increased with the depth of invasion and stage of the disease. It also varied significantly in tumors different in the gross type and serosal involvement. CONCLUSION: To detect CEA in peritoneal washings by RT-PCR and RIA, and to examine them for tumor cells by cytotogic method are useful to predict subclinical metastasis to the peritoneam in patients with gastric carcinoma, but RT-PCR is most sensitive.