Corelation of Homologous Recombination Repair System by Studying a Single-nucleotide Polymorphism in Xrcc3 Gene with Initiation and Progression of Colorectal Cancer

Colorectal cancer is the third cause of cancer death in western countries. Age, inadequate diet, obesity, inactivity and genetic changes are some of the risk factors of colorectal cancer. Corelation of genetic diversity in homologous recombination repair system with cancer was evaluated in many recent studies. This study was done to investigate the correlation of T241M polymorphism in Xrcc3 gene and colorectal cancers. In this cross-sectional study after collecting blood samples and extraction genomic DNA, genotype distribution of the polymorphism was determined by RFLP-PCR (Restriction fragment lengh-polymerase-Polymerase chain reaction) method. A significant corelation between T241M polymorphism with colorectal cancer was seen. Age and family history were also corelated with this cancer. Although, there was no statistically relationship between smoking status and colon cancer, but it showed correlation with rectum cancer and it has been also observed that the most occurance of metastatic activity is in the rectum. According to our study T241M polymorphism in Xrcc3 gene from homologous recombination repair systm could be a suitable factor for early diagnosis of colorectal cancer especially rectum and its co-operation with smoking status.