Multiple colon tumors. Diagnosis and follow-up of 450 patients with colorectal carcinoma.

Objective: Failure to diagnose synchronous tumors leads to errors in patient treatment and prognosis. The existence of metachronous tumors requires strict patient follow-up to ensure early identification of the second tumor. The present study evaluates the results obtained in the application of a structured procedure for the diagnosis and follow-up of multiple colorectal carcinoma.

Methods: A structured procedure was used to follow for 5 years a group of 12 patients with multiple colorectal tumors (7 synchronous and 5 metachronous) of a series of 450 colorectal neoplasms.

Results: Six synchronous tumors were diagnosed preoperatively and one intraoperative. Of the 5 metachronous neoplasms, 4 strictly adhered to the follow-up protocol, as a result of which the second tumor was detected at an early stage. The remaining case involved no follow-up, and the second tumor was diagnosed in an advanced stage as a result of bowel occlusion. The left colon was predominantly involved; polyps were detected in 9 cases, while two patients had 3 malignancies detected by histopathological study.

Conclusions: We emphasize the need for a full evaluation of the colon in all patients with colorectal carcinoma. In the case of incomplete preoperative evaluation, intraoperative colonoscopy is to be considered; if this is not feasible it should be performed one month after surgery. A structured follow-up procedure permits the early detection of these tumors, there by improving patient prognosis.