A prospective evaluation of serum carcinoembryonic antigen (CEA) levels in the management of colorectal carcinoma.

The relationship between the pattern of carcinoembryonic antigen (CEA) changes and the types of recurrence was investigated in a prospective study of 146 patients who underwent curative operations for adenocarcinoma of the colon or rectum. Recurrences developed in 51 patients (34.9%) and was local in 14, distant in 23, and both local and distant in 14 of them. CEA slope values were individually calculated beginning with an initial rise of more than 1 ng/ml, and expressed as the % rise in CEA per month. Patients who relapsed had significantly higher slopes than those who remained well (median 20.0% versus 0.3% rise,p0.001). A slope value of 5% rise per month broadly separated the two groups with an overall accuracy of 79.4%, sensitivity rate for recurrence of 86.3%, and specificity rate for no relapse of 75.8%.