Changes in serum levels of CEA and CA19-9 tumor markers in different stages of patients with colorectal cancer

Colorectal cancer is one of the most common gastrointestinal cancers worldwide with a high prevalence among middle-aged people. This study aimed to evaluate and compare changes in serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), as two important tumor markers, in the diagnosis of different stages of colorectal cancer.

This basic research was conducted on hospitalized patients with colorectal cancer (n=67). At first, tissue samples and venous blood samples were collected from patients. Subsequently, CEA and CA19-9 tumor markers were measured by enzyme-linked fluorescence assay and cellular changes were investigated by hematoxylin and eosin staining.

In this study, 57.6% and 43.3% of the patients were male and female, of which 59.7% (40 patients) cases were over 61 years old. The most common sites of tissue involvement were found to be the rectum and sigmoid. In the acute phase of the disease, a decrease was observed in the number of red blood cells (P=0.0091) and the level of hemoglobin (P=0.141); however, the number of platelets remained unchanged (P=0.212). In addition, lymphocyte and neutrophil counts increased at first, while they decreased later. The findings showed that there was a significant relationship between these two tumor markers and disease levels.

Our results indicated that although these tumor markers are not suitable factors for the diagnosis of this cancer in the early stages, they can be used as two important markers to diagnose the progression of the disease.