Evidence for an association of TP53 codon 72 polymorphism with sporadic colorectal cancer risk in Isfahan

BACKGROUND: A common polymorphism at codon 72 of TP53 gene has been associated with increased risk for many human cancers. We studied this TP53 polymorphism in colorectal adenocarcinomas in small population selected from Isfahan city. METHODS: Samples: We undertook a case-control study on 180 controls and 180 paraffin block specimens of sporadic colorectal adenocarcinomas. PCR amplification of TP53 codon 72 polymorphism: TP53 codon 72 genotypes were detected by PCR using specific primer pairs for amplifying the Proline or the Arginine alleles. STATISTICAL ANALYSES: The χ2-test was used to assess the significance of any difference in the prevalence of TP53 codon 72 polymorphism between colorectal cancer patients and controls. RESULTS: In control samples, the genotype distribution for TP53 polymorphism showed 28.3%, 48.9% and 22.8% for the Arginine/Arginine, Arginine/Proline and Proline/Proline genotypes, respectively. In the cancer group 40% of the cases were Arginine/Arginine, 42.2% were Arginine/Proline and 17.8% were Proline/Proline. A significant difference between cases and controls was found for the Arginine/Arginine genotype compared with (grouped) Arginine/Proline and Proline/Proline genotypes (Odds Ratio = 1.686 (1.085-2.620), P = 0.02). CONCLUSIONS: TP53 codon 72 polymorphism may be a genetic predisposing factor for colorectal adenocarcinomas in Isfahan city.