CARCINOEMBRYONIC ANTIGEN LEVELS IN THE PERITONEAL-CAVITY - USEFUL GUIDE TO PERITONEAL RECURRENCE AND PROGNOSIS FOR GASTRIC-CANCER

At the time of laparotomy, peritoneal washings were collected from 155 gastric cancer patients and the levels of carcinoembryonic antigen (C EA) determined. The CEA levels in peritoneal washings were statistical ly independent of those in sera and could more reliably predict the pr esence of peritoneal metastasis than a cytologic study. Peritoneal rec urrence was seen in 14 of 118 patients after curative operation. Of th e 14 patients, 10 (71%) had elevated levels of CEA (100 ng/g protein) at surgery. Of these 10 cases, 2 of the tumors were classified as stag e IB and 4 had no serosal invasion. Only one patient with peritoneal m etastasis and a low CEA level was free from relapse more than 1 year a fter operation. Kaplan-Meier's analysis showed that a high CEA level i n peritoneal washings was a predictor of poor prognosis in patients wh o underwent either curative or noncurative resection. A proportional h azards regression analysis showed that a high CEA level in peritoneal washings was statistically significant in terms of predicting a shorte r interval until peritoneal recurrence (p = 0.0002) and for survival ( p = 0.0001). The CEA level in peritoneal washings is therefore of valu e as an indicator of peritoneal recurrence and prognosis.