[Using CEA for diagnostic, therapeutic and prognostic evaluation in colorectal cancers]

Serum CEA measured by radioimmunoassay was studied in 63 colorectal cancer patients. The present study was designed to assess the usefulness of serum CEA assay on the diagnosis of colorectal cancer at various stages and in the care of prognosis. CEA was examined before and after surgery at appropriate intervals. Serum CEA test was positive (over 2.5 ng/ml) in 10.5% of the 19 patients with Dukes stage A, in 61.9% of 21 patients with Dukes stage B, and in 78.3% of 23 patients with Dukes stage C. Curative resection was able to perform in all of colorectal cancer patients with values of less than 2.5 ng/ml, in 75% of them with values of 2.5-10 ng/ml and in 45% of them with values of greater than 10 ng/ml. High serum CEA levels decreased to normal levels within 1-3 months after curative resection. High CEA levels were observed before the secondary operation in 4 out of 5 patients who underwent reoperation because of the evidence of recurrence. CEA decreased to normal levels in 3 of them and increased to 500 ng/ml in 1 case. In the last case CEA sustained high levels until the death due to metastasis to the lung and lymph nodes.