Diagnostic value of preoperative serum carcinoembryonic antigen and carbohydrate antigen 19-9 in colorectal cancer

Background Since the first introduction of tumour markers, their usefulness for diagnosis has been a challenging question. The aim of the present prospective study was to investigate, in colorectal cancer patients, the relationship between preoperative tumour marker concentrations and various clinical variables. Methods The study prospectively enrolled 131 consecutive patients with a confirmed diagnosis of colorectal carcinoma and 131 age- and sex-matched control subjects with no malignancy. The relationships of the tumour markers carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 with disease stage, tumour differentiation (grade), mucus production, liver function tests, T stage, N stage, M stage were investigated. Results Serum concentrations of CEA were significantly higher in the patient group than in the control group (p = 0.001); they were also significantly higher in stage III (p = 0.018) and IV disease (p = 0.001) than in stage I. Serum concentrations of CEA were significantly elevated in the presence of spread to lymph nodes (p = 0.005) in the patient group. Levels of both tumour markers were significantly elevated in the presence of distant metastasis in the patient group (p = 0.005 for CEA; p = 0.004 for CA 19-9). Conclusions Preoperative levels of CEA and CA 19-9 might provide an estimate of lymph node invasion and distant metastasis in colorectal cancer patients.