Detection of Epstein-Barr virus in colorectal cancer and Polyp by using PCR technique

Colorectal cancer is the most common gastrointestinal cancer and the second leading cause of cancer deaths worldwide. The purpose of this study is to investigate the prevalence of Epstein-Barr virus in patients with colorectal carcinomas and polyps in comparison with healthy people. In this analytical case-control study, 15 patients with colorectal cancer and 20 patients with colorectal polyp were studied. From each patient two tissue samples were collected: one sample of the malignant tissue and one sample of normal colorectal tissue from an area located 15 cm away from the malignant tissue. Also the 35 patients without malignancy as controls were sampled. Biopsy specimens were frozen under sterile conditions at -20. After DNA extractions, analysis of PCR to detect EBV DNA in tissue samples was performed with chi square test. EBV DNA were found in 60% of tumor samples (9 of 15), in 35% of polyp samples (7 of 20) and 40% of the non-malignant control group (14 of 35). Two cancer patients (13.3%) and five polyp patients (25%) had EBV DNA detected in both the tumor and the matched normal tissue. Statistical analysis showed no significant association between the prevalence of EBV and incidence colorectal cancer and polyps according to the location of the sample in comparison with the control group (p = 0.44). The results of the present study demonstrate the presence of EBV sequences in differentiated cancer tissue, polyp and non-malignant by PCR method reflects the ability of the virus to infect of the different colon cells.