Purpose: Single nucleotide polymorphism (SNP) at position -309 (T309G) in MDM-2 promoter induces tumor formation in the individuals possessing inherited p53 mutations. The present study was undertaken to investigate the association of MDM-2 SNP309, p53 Arg72Pro, and p53 intron-6 G/A polymorphism with total, premenopausal, and postmenopausal breast cancer risks in Indian women.
Methods: Genotyping of MDM-2 SNP309, p53 Arg72Pro, and p53 intron-6 G/A in 104 patients and 105 controls was performed either by ARMS-PCR or by polymerase chain reaction and direct sequencing.
Results: The p53 Arg72Pro heterozygous variant and in combination with its homozygous variant exhibited a significant protective association with total (odds ratio [95% confidence interval]: 0.42 [0.22-0.81] and 0.46 [0.25-0.85], p value; 0.007 and 0.012) and postmenopausal breast cancer risk (odds ratio [95% confidence interval]: 0.25 [0.07-0.73] and 0.27 [0.08-0.77], p value; 0.009 and 0.013]. Neither combined nor homozygous/heterozygous MDM-2 SNP309G was associated with total, premenopausal, or postmenopausal breast cancer risk; however, MDM-2 SNP309G, along with p53 Arg72Pro heterozygous variant, showed a significant protective association with premenopausal breast cancer risk (odds ratio [95% confidence interval]: 0.18 [0.02-1.20], p value; 0.041 for homozygous + heterozygous MDM-2 SNP309G).
Conclusions: The results indicate protective associations of p53 Arg72Pro heterozygous variant with postmenopausal and MDM-2 SNP309G along with p53 Arg72Pro heterozygous variant with premenopausal breast cancer risk.