Programmed death protein 1 (PD1) mRNA expression as a screening and diagnostic tool in colon cancer

Abstract

Purpose: Colon cancer is one of the most frequent malignant tumors worldwide. Studies showed that in patients with colon cancer, immune system is generally compromised. Correlation of PD1 expression and numerous types of cancer such as colorectal cancer have been well illustrated. The higher levels of PD1 expression correlates with poorer prognosis. In our study, we aim to investigate the associations between PD1 gene expression and susceptibility to CRC. Methods: This study was carried out on 50 patients with colon adenocarcinoma, 50 patients with benign colon polyp and 50 apparently healthy persons served as controls. All subjects were exposed to full history taking, general clinical examination. Complete blood count, liver and kidney function, determination of serum tumor markers (CEA and CA19-9). Estimation of PD1 Gene expression by real-time PCR was done. Results: The mean PD1 gene expression was 5.8% in cancer patients compared to 0.9% in benign polyps group and 0.04 in normal people. The sensitivity and specificity of PD1 expression in our study was 98% and 95% respectively. Higher PD1 gene expression had statistically significant relation with tumor stage (p=0.001) and presence of metastases (p=0.003). Conclusions: The level of PD1 can be used to differentiate between colon cancers and begin adenomas. PD1 could be used as a prognostic marker in colon cancer.