The clinical usefulness of preoperative CEA determination in gastric cancer.

Between 1980 and 1984, preoperative serum carcinoembryonic antigen (CEA) was determined in 468 patients with gastric cancer to evaluate its clinical usefulness. The positive rate of preoperative CEA was 20.9 per cent in these 468 patients. A significantly higher CEA positive rate was obtained in those patients with liver metastasis (69.2 per cent), n3-4 (40.0 per cent), stage IV gastric cancer (37.0 per cent) and Pap, Tub1 histological type (26.3 per cent) (p less than 0.01). It is interesting that the positive rate of the 49 unresectable patients was 51.0 per cent, which was significantly higher than 17.4 per cent of the 419 resectable cases (p less than 0.01). CEA levels in 16 of the 39 patients with liver metastasis were more than 100 ng/ml. In contrast, serosal invasion and peritoneal metastasis were less correlated to the CEA positive rate. In the 419 resected cases, the 5 year survival rate in the higher CEA group of more than 50 ng/ml (35 cases) was 4.4 per cent, which was significantly lower than 64.0 per cent in the negative group (346 cases) (p less than 0.01). These results show that CEA determination in patients with gastric cancer is useful for the prediction of prognosis, as well as for a diagnostic tool to discover the presence of liver or lymph node metastasis.