CEA and CA19-9 in Patients with Colorectal Cancer

Abstract

Colorectal cancer is the most common cause of death in Thailand. The early diagnosis of colon and rectal cancers is important because it can increase the chances of cure and survival rates for patients. For laboratory testing, the detection of tumor markers in clinical samples can be used for diagnosis, prognosis, and monitoring treatment outcomes. This study aimed to evaluate the efficacy of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in differentiating patients with colorectal cancer from benign colon tumors, and to evaluate the relationship of CEA and CA19-9 cancer markers with various pathological parameters among colorectal-cancer patients. The 105 patients and 22 benign colon tumors treated at the National Cancer Institute were detected for CEA and CA19-9. It was found that CEA levels among patients with colorectal cancer were higher than those with benign tumors (P=0.006), while CA19-9 level did not differ significantly between the two groups (P=0.116). In addition, the sensitivity of using CEA and CA19-9 parameters to differentiate patients with colorectal cancer from benign colon tumors were 56.19 % and 26.67 %, respectively. The sensitivity of combined detection using CEA and CA19-9 was higher than either marker alone (60.00%). The present study showed that CEA can better discriminate between patients with colorectal cancer and benign colon tumors than CA19-9 (the areas under the ROC curve (AUC) were 0.70 and 0.61 for CEA and CA19-9, respectively). CEA and CA19-9 serum concentrations were also significantly higher in stage IV disease than stage I-III, and significantly elevated in the presence of distant metastasis (P=0.000), but the levels of both tumor markers were not significantly associated with tumor localization and lymph-node metastasis.