P53 gene polymorphisms and breast cancer risk in Arab women.

The association between polymorphisms in the p53 tumor suppressor gene and breast cancer risk has been studied in many human populations with conflicting conclusions. However, similar studies in Arab women are not available, and the status of these polymorphisms in this ethnic population is not known. We investigated the status of four known p53 gene polymorphisms and their possible role in breast cancer risk in Arab women. Genotyping was performed for 288 breast cancer women and 188 controls to determine Pro47Ser, Arg72Pro, Intron 3 Ins16 bp and intron 6 (G > C) polymorphisms. The p53 variant Pro47Ser was detected only in one Kuwaiti breast cancer patient and was not detected in any of the control subjects. Frequency of Arg/Arg at codon 72 was 26.6% in controls and 28.1% in patients, Arg/Pro frequency was 59.6% in controls and 69.4% in patients, the Pro/Pro genotype was 13.8% in controls and 2.4% in patients. We observed that women with Pro/Pro genotype have decreased risk for developing breast cancer (OR=0.166, 95% CI=0.067-0.411, p<0.001). The intron 3 genotypes were A1/A1 (48.9%), A1/A2 (40.6%) and A2/A2 (10.5%) in controls and A1/A1(42.4%), A1/A2 (52.8%) and A2/A2 (4.8%) in cases. The intron 6 genotypes were 92.4% (GG), 7.6% (GC) and 0% (CC) in controls and 96.5% (GG), 3.5% (GC) and 0% (CC) in cases. No statistically significant differences between patients and controls were observed for intron 3 and intron 6 polymorphisms. Our data show that proline homozygosity at p53 codon 72 is associated with decreased breast cancer risk in Arab women.