Patients (n = 464) with colorectal carcinoma in stages A to D2 were studied; 230 had CEA determined preoperatively and 433 serially. Actuarial life table analysis and the Mantel-Cox test showed that overall 5-yr survival was 59.2% and that the differences among the stages were highly significant. Survival rates for patients with CEA over the cutpoints at 3.2, 5, 10, and 20 ng/ml decreased from 53.8% to 21.9%. When analyzed in Cox multivariate regression, stage, initial CEA, age, and location of cancer affected survival. Postoperatively, three CEA patterns were found: 1) CEA was always normal; 2) initially elevated CEA was decreasing to the normal range to remain so thereafter; or 3) CEA started to increase from any nadir some time after surgery. The 5-yr survival rate was 73.3% for patients with the normal, 44.5% with the decreasing, and 30.1% with the increasing CEA pattern. When the postoperative CEA, pattern was added to the preoperative covariates in 196 patients for whom both the initial CEA, and postoperative patterns were available, only the stage, postoperative CEA pattern, and location of cancer affected survival. After elimination of initial CEA 433 patients with postoperative serum were analyzed, and again, only stage, postoperative CEA pattern, and location of cancer appeared to affect survival. Stage of disease, initially elevated serum CEA, age over 60 yr, location of cancer in the rectum, and CEA increasing after surgery appear to be independent ominous prognostic indicators.