Prognostic Value of Carcinoembryonic Antigen (CEA) and Carbohydrate Antigen (CA19-9) in Colorectal Cancer

Abstract

The present study analysed the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19 9 (CA19 9) in correlation with clinicopathological variables and survival outcomes in Libyan patients with colorectal cancer (CRC). The clinicopathological variables of 397 patients with CRC di-agnosed at the National Cancer Institute in Misurata, Libya, between 2008 and 2017 were retrospec-tively analyzed. Blood samples from these patients were analyzed for serum CEA and CA19 9 levels before treatment by electrochemiluminescence immunoassay (double antibody sandwich ELISA) on a Roche cobas e 602 modules. The relationships between CEA CA19 9 expressions (separately and combined) with clinicopathologic variables and survival outcomes were analyzed using the Kaplan Meier method, log rank test and Cox regression analyzes. Cut off values for serum CEA and CA19 9 levels were 5 ng/ml and 37 U/ml, respectively. The mean serum levels of CEA and CA19 9 for all CRC tumors were 70.0 ng/ml and 473.0 U/ml, respectively. Tumors with higher serum CEA and CA19 9 levels were found in 60.0% and 46.0 % of CRC cases. Higher CEA and CA19-9 expression were significantly associated with more indicators of a malignant phenotype, including a young age <50 years, high histological grade, large tumor size, positive lymph nodes, advanced stage and distant metastases. The median follow-up duration was 46 months and 44.3% of patients had died of CRC. Patients with higher expression of the biomarkers CEA and CA19-9 had shorter overall survival and lower disease-free survival. Patients with both tumour markers increased showed a remarkably shorter 5-year survival rate (29.3%) and lower disease-free survival rate (p<0.0001). The Cox regression analysis emphasizes these results (p value < 0.0001). The combination of CEA and CA19-9 appear as an independent prognostic marker for survival. More intensive therapy in patients diagnosed with an advanced CRC with combined elevation of tumor markers (CEA and CA19-9) is highly considered. Measuring CEA and CA19-9 preoperatively in CRC patients is highly significant and could be useful as a prognostic marker.