Carcinoembryonic antigen (CEA) as a prognostic and monitoring test in clinically complete resection of colorectal carcinoma.

The prognostic and postoperative monitoring capabilities of the CEA assay were compared to pathological staging of the operative specimens, clinical followup including endoscopy, radiology and scanning techniques, as well as DNCB skin testing and laboratory enzyme determinations (alkaline phosphatase and transaminase). A total of 46 patients with curative resection for colorectal carcinoma were studied. This included 23 patients with recurrent tumors compared to 23 long-term survivors without signs of recurrence at the time of the study. Preoperative CEA determinations were a good prognostic tool comparable to pathological staging of the specimen. Post operative CEA monitoring was the earliest sign of recurrence in 14 of 23 patients and was positive at the time of recurrence determined by other methods in 20; it was negative in only three cases. The incidence of false positive results among the non recurrent group became a lesser problem when repeated elevated values were required before considering the patient as having a recurrence. From these data, it seems reasonable to propose the use of a second-look operation in patients with maintained elevation of circulating CEA and no clinical signs of tumor presence, if we are to treat recurrence at an early stage. Chemotherapy would be an alternative way to deal with this problem, since the absence of clinical signs in general correlate with small bulk of tumor which at this time may be more susceptible to chemotherapeutic agents.