[Evaluation of p53 codon 72 polymorphism in adenocarcinoma of the colon and rectum in Guilan province]

ABSTRACT

Colorectal cancer is the second cause of mortality in developed countries. The p53 gene and some of it's polymorphisms are among the causes for cancer development. The purpose of this study is to evaluate the relationship between the p53 codon 72 polymorphism in colorectal adenocarcinoma specimens compared with controls. We performed a case-control study among 112 patients with colorectal carcinoma and 112 controls in Rasht, Iran. Different genotypes of codon 72 were determined by allele-specific polymerase chain reaction [PCR]. The frequency of the Arg/Arg genotype of the p53 codon 72 polymorphism was 35.7%, for Arg/Pro it was 50.9%, and for Pro/Pro it was 13.4% in colorectal cancer patients. Among controls, the Arg/Arg genotype was seen 37.5%, Arg/Pro was noted in 50%, and Pro/Pro was seen in 12.5% [p = 0.95]. When tumor location was taken into consideration, 68.8% of the Arg/Arg carrier genotypes were associated with an increased incidence of left colon cancer. There was a significant statistical relationship between expression of the Arg allele in colorectal cancer samples and metastases [p=0.003]. The majority of colorectal cancer patients with p53 Arg homozygosity had left-sided colon cancer. There was also a relation between p53 Arg homozygosity, lymph node involvement, and metastases. Thus, we have suggested that the correlation between this polymorphism, tumor risk, and metastasis should be studied to determine its effectiveness as a diagnostic factor