Serial determinations of serum CEA in monitoring management of patients with colorectal carcinoma.

Serum concentrations were determined serially in two groups of patients with colorectal carcinoma: in 123 after curative resection and in 34 with residual cancer. Of the first group, in 98 serum CEA fluctuated within the normal range or with a 2-fold larger amplitude evidencing effective surgery because only 9 had recurrence; in 25 serum CEA rose persistently from a postoperative nadir indicating relapse, mostly liver metastases. Of the 34 patients with relapse, 3 had clinically and 7 CEA-directed second-look laparotomy; although 7 had operation with curative intent, only 3 remained disease-free. In the second group, there were 26 patients after palliative surgery and 8 during nonsurgical treatment. Serum CEA fluctuated within the normal range in 2 patients in remission and in 3 with progressive cancer, and rose in parallel to cancer progression in 29. Thus, serum CEA within or slightly above the normal range was 88% predictive that the patient might be free of disease or in remission; whereas elevated or rising level indicated disease progression. Accordance between serum CEA and clinical status occurred in 145 of 157 (92%) patients.