[Prognostic study of preoperative serum levels of CEA and CA 19-9 in colorectal cancer].

Purpose: Carcinoembrionic Antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) are the most frequently used tumor markers in the clinical setting of colorectal cancer. The aim of this study is to evaluate the prognostic value of preoperative serum levels of CEA and CA 19-9 in colorectal cancer patients.

Methods: Serum levels of CEA and CA 19-9 were examined in 586 patients with colorectal cancer. Cut-off levels were calculated at reference value:<2.5 ng/mL (group A) versus >2.5 ng/mL (group B) for CEA and, <37 U/mL (group A) versus >37 U/mL (group B) for CA 19-9.

Results: According to tumor progression, each marker tended to show a higher level. Group A showed a significantly better prognosis than group B in both CEA and CA 19-9. In Dukes classification A, B and C, only CEA showed a better prognosis in group A than group B. At the time of recurrence compared to the pre-operative point, the CEA and CA 19-9 levels were significantly higher in both group A and B, however. In relation to the necessity of adjuvant chemotherapy (5-FU containing regimen) in Dukes A, the cases without adjuvant chemotherapy in group B of CEA showed a poor prognosis.

Conclusion: The measurement of preoperative serum CEA and CA 19-9 is useful for prognostic prediction in colorectal cancer. Cut-off levels calculated at the reference value reflect the prognosis in this study. Especially, preoperative CEA reveals a potential high risk group in Dukes A which should be carefully treated by adjuvant chemotherapy to avoid recurrence.