The usefulness and limitations of CEA assay in the management of colorectal cancer

We investigated the usefulness and limitations of the measurement of CEA in the evaluation of tumor resection and the detection of recurrence in colorectal cancer patients. Preoperatively, 46 of 90 patients (51.1%) had CEA values of 5.0 ng/ml or higher. The percentage of patients with elevated CEA in whom the CEA values returned to normal one month postoperatively was significantly higher in those who had undergone a curative resection than in those who had undergone a non-curative resection (p<0.02). Among patients with normal CEA values, the changes were nil or only slight in CEA values, one month postoperatively Among 28 with recurrences, 24 (85.7%) had CEA values of 5.0 ng/ml or higher. All 11 with liver recurrences had values of 10.0 ng/ml or higher. In 4 with liver recurrences and in cases where CEA measurements were made, CEA values were found to be abnormal 3 to 10 months before the recurrences and a rapid elvation occurred for a short period. However, 4 out of 10 with local or lymphnode recurrences showed normal CEA values. CEA measurement was useful in detection of liver recurrences, but not so useful in detecting local or lymphnode recurrences.