Reoperation directed by carcinoembryonic antigen level: the importance of a thorough preoperative evaluation.

Many asymptomatic patients suspected to have recurrent colorectal cancer based on an elevated carcinoembryonic antigen level will be spared unnecessary operation if strict attention is paid to their preoperative evaluation. Liver and renal function should be assessed. Unresectable extraabdominal and intraabdominal recurrence or metastases should be excluded. Patients being evaluated for recurrence after curative resection of a rectosigmoid cancer should undergo a bone scan. Having satisfactorily ensured normal results for these investigations, the surgeon should then proceed to search for an intraabdominal source of tumor recurrence.