Association of p53 Codon Arg72Pro and p73 G4C 14-to-A4T14 at exon 2 genetic polymorphisms with the risk of Japanese breast cancer

Background: The association between breast cancer risk and genetic polymorphisms of p53 at codon 72 (Arg72Pro) has been investigated by several studies, but the results are not consistent. The aim of this case-control study conducted in Nagoya Japan, was to reconfirm the results of prior studies of polymorphisms of p53 Arg72Pro, and to test if polymorphisms of p73 G4C14-to-A4T14 at exon 2 (G4A) were also associated with breast cancer risk. Methods: The cases were 200 breast cancer patients who visited Aichi Cancer Center Hospital. The controls were 282 local citizens who underwent a health check-up. All cases and controls were recruited from Chubu Japan. Genotyping was carried out by polymerase chain reaction with confronting two-pair primers. Results: The p53 genotype distribution was 40.4% for Arg72 homozygous, 48.9% for heterozygous, and 10.7% for Pro72 homozygous in controls, and 32.0%, 50.0%, and 18.0% in cases, respectively. A comparison between cases and controls indicated a significantly increased risk for Pro72 homozygosity in cases (odds ratio = 2.14; 95% confidence interval = 1.21-3.79). The genotypic frequencies for p73 G4A were 54.3% for G/G, 39.7% for G/A, and 6.0% for A/A in controls; and 59.0%, 32.0%, and 9.0% in cases, respectively. There were no significant differences in p73 G4A frequency between cases and controls. Conclusions: This study implies an association of breast cancer risk with the p53 polymorphism Arg72Pro, but not with p73 G4A.