The Prognostic Value of Preoperative Serum Levels of CEA and CA 19-9 in Patients with Colorectal Cancer

Abstract

Aim: Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) are the most frequently used tumor markers in clinical evaluation of colorectal cancer patients. In this study, we investigated the prognostic significance of CEA and CA 19-9 in colorectal cancer patients without distant metastasis. Method: We assessed colorectal cancer patients with measured preoperative serum CEA and CA 19-9 levels between 1993 and 2004. Peripheral venous blood samples were taken before surgery. Tumor marker analyses were accomplished with a two-site immuno-radiometric assay. Patients’ demographic, clinico-pathological and treatment data were retrieved from the patients files. Results: A total of 548 patients were included. Mean age was 59.6±12.3 years and 52.5% were male. Serum CEA and CA 19-9 levels were positive (above the cut-off values) in 190 (34.6%) and 97 (17.7%), respectively. In the univariate analyses, CEA and CA 19-9 positive patients showed poorer cancer-specific survival rates than marker negative patients (log-rank x2=16.935, p<0.001 and log-rank x2=12.431, p<0.001, respectively). In multivariate Cox analyses, CEA (p=0.003) and CA 19-9 (p=0.001) had independent prognostic significance. When CEA and CA 19-9 were included together in the Cox analysis, CEA (relative risk=1.39, 95% confidence interval (CI)=1.03-1.88, p=0.030) and CA 19-9 (relative risk=1.64, 95% CI=1.15-2.33, p=0.006) maintained their independent prognostic significances. Conclusion: Preoperative serum CEA and CA 19-9 have prognostic importance independent of clinico-pathological factors in colorectal cancer patients without distant metastasis. These tumor markers can be used in the planning of adjuvant therapy of colorectal cancer patients.