The Importance of Determining Preoperative Serum Concentration of Carbohydrate Antigen 19-9 and Carcinoembryonic Antigen in Assessing the Progression of Colorectal Cancer

Introduction: Many evidence indicates that Carcinoembryonic antigen (CEA) and Carbohydrate antigen 19-9 (CA 19-9) have strong reactivity with tumor cells and may serve as a useful marker in identifying patients with colorectal cancer (CRC). Objectives: The goal of this study was to evaluate the relationship between preoperative concentration of serum levels of CEA and CA 19-9 and progression of colorectal cancer. Methods: The retrospective study included 80 patients operated for colorectal cancer at the Clinic for General and Abdominal Surgery, Clinical Center of University of Sarajevo, from 2013 to 2018. The following clinical and laboratory parameters were observed: age, sex, preoperatively measured concentrations of CEA and CA 19-9 antigens, CRC localization, postoperative histopathological findings and CRC stage (TNM classification). All of the data above were processed by relevant statistical methods, with an accepted level of statistical significance of p <0.05. Results: The highest serum levels of CEA and CA 19-9 were observed in stage IV of CRC. Average CEA and CA 19-9 values did not differ significantly between tumor stages (p>0.05). Preoperatively measured serum concentrations of CEA and CA 19-9 in patients with CRC were significantly correlated (rho = 0.328, p = 0.001). An increase in the depth of tumor invasion of the intestinal wall tumor (pT) is followed by an increase in the serum value of the CEA marker, but this ratio was not statistically significant (rho=0.194, p=0.080), while the relationship between depth of intestinal wall invasion and serum level of CA 19-9 was significantly positive correlation (rho = 0.252, p = 0.024). However, the linear regression analysis model showed that serum levels of CEA and CA 19-9 could not be predictors of CRC stage and depth of tumor invasion of the intestinal wall (p> 0.05). Conclusion: Preoperatively measured serum values of CEA and CA 19-9 cannot indicate the specific stage and histopathological size of the CRC.