We tested 27 different combinations (XRCC1, TP53, MDM2) and found that the interaction of Arg399Gln/Arg72Pro/T309G of genes XRCC1/TP53/MDM2 heterozygous genotypes was associated with BC (χ2 = 5.04; р = 0.025) and increased its likelihood with an OR of 6.40 (95% CI 1.18–34.63). This evidence concerns the gene MDM2 and breast cancer.