Analysis of the R72P polymorphism of the TP53 gene in patients with invasive ductal breast carcinoma

Breast cancer is the most common neoplasia as well as the main cause of cancer-related death among women, experiencing a 0.5% increase in incidence per year. The disease results from a series of mutations in the DNA development and repair genes. Approximately 50% of human carcinomas present mutations in the TP53 gene. Polymorphisms of TP53 include codon 72 containing either arginine (CGC) or proline (CCC). Such polymorphisms may be involved in the susceptibility and predisposition to cancer, presenting a widely variable ethnic and geographic distribution. The arginine homozygous genotype seems to be a significant risk factor for breast cancer. The purpose of this study was to determine the frequency of the R72P polymorphism of the TP53 gene in patients with invasive ductal breast cancer from southern Brazil, where this type of cancer has a high incidence, as well as its association with breast carcinoma and clinicopathological characteristics. Seventy-six patients suffering from invasive ductal breast cancer and 80 controls were analyzed, and samples were evaluated by PCR followed by restriction enzyme digestion. No statistical differences in terms of the genotype frequency (P=0.707) or the arginine and proline allele frequencies (P=0.469) involving codon 72 were found in patients compared to controls. Thus, statistical analysis did not suggest any association between the R72P polymorphism of the TP53 gene and invasive ductal carcinoma in the population studied. Additionally, no significant association with the clinicopathological characteristics presented by the breast carcinoma patients was found.