The value of combined tumor markers of CEA, CA19-9 and CA242 for diagnosis of patients with colorectal cancer

Objective To explore the clinical value of serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9(CA19-9) and carbohydrate antigen 242(CA242) levels in patients with colorectal cancer using single item and multi-items determination. Methods Serum levels of CEA, CA19-9 and CA242 were measured with chemiuminescent immunoassay (CLIA) and radioimmunoassay (RIA) in 89 cases of colorectal cancer patients and 50 cases of normal people. Results The serum levels of this three tumor markers were significantly higher than those in the control group (t=2.97, 3.55 and 7.44, P＜0.01). Combined determination of those three obviously excels that two items (CA242+CA19-9 and CEA+CA19-9) or single item, there was statistical significance (x2=30.552, 32.076, 18.365, 7.130 and 8.862, P＜0.01). Combined determination of those three could enhance the sensitivity (85.39%) and accuracy(90.60%), but the specificity was decreased (88.00%). Conclusion Determination of serum CEA, CA19-9 and CA242 levels are valuable for the diagnosis and evaluation of patients with colorectal cancer, and the diagnosis sensitivity can be enhanced with combined determinations. Key words: Colorectal neoplasms;  Carcinoembryonic antigen;  CA-19-9 antigen;  CA-242 antigen; Radioimmunoassay