RÉSUMÉ
Background: Breast cancer is one of the most common cancers in Iranian women. The p53 gene plays a principal role in genomic stability, and its function varies according to polymorphisms. The aim of our study was to determine the relationship between the intron3 16bp duplication polymorphism of the p53 gene and breast cancer in Iranian women. Materials and Methods: We performed a case-control study among 145 patients with invasive ductal carcinoma of the breast and 145 controls in Isfahan, Iran. The distribution of the intron3 16bp duplication polymorphism was determined by polymerase chain reaction (PCR). The relationship between clinicopathological data and the PIN3 polymorphism was examined using chi-squared analysis. Results: A significant difference was observed in the polymorphism variants in breast cancer specimens compared with controls (P < .001). Among the cancer patients, 59.9% were below the age of 50 years; and 67.5% of the patients in this group had the intron3 16bp duplication polymorphism. Conclusions: PIN3 Ins 16bp duplication polymorphism is a genetically predisposing factor for breast cancer development in Iranian women and may be causal in patients under the age of 50 years.