Carcinoembryonic antigen levels in peritoneal washings can predict peritoneal recurrence after curative resection of gastric cancer.

Carcinoembryonic antigen (CEA) levels were determined in the peritoneal washings from 120 patients with gastric cancer and 9 patients with benign diseases. Elevated values (greater than 100 ng/g of protein) were observed in 20 of 25 patients with gastric cancer with visible dissemination and 16 of 25 patients with serosal invasion but no dissemination. The same elevation was found in only 9 of 70 patients with no serosal invasion and none of the patients with benign disease. The 2-year survival rates after curative operation for the patients with and without elevation of CEA levels were 21% (19 patients) and 100% (66 patients), respectively (P less than 0.001). A negative correlation was found between CEA levels and survival times after noncurative operation. These results indicate that the CEA level in peritoneal washings could be a sensitive detector of invisible peritoneal dissemination and a new predictor for the postoperative prognosis of gastric cancer.