The p53 R72P polymorphism does not influence cervical cancer development in a Portuguese population: a study in exfoliated cervical cells.

The interaction between the E6 protein of the high-risk human papillomaviruses (HPVs) with p53 seems to be crucial in cervical carcinogenesis. The presence of Arg/Arg genotype at codon 72 of TP53 gene was characterized as a risk factor in development of cervical cancer. However, the role of this polymorphism remains controversial and some authors suggested that the origin of DNA (blood or exfoliated cervical cells) might influence these results. This study analyzed the effect of the p53 codon 72 polymorphism (R72P) in exfoliated cervical cells of women from the northern region of Portugal using two methodologies: allele-specific polymerase chain reaction and real-time polymerase chain reaction. We studied 700 cervical exfoliated cells which showed: 334 cases from women without cervical cancer or cervical lesion (N), 114 low-grade squamous intraepithelial lesions (LSIL), 107 high-grade squamous intraepithelial lesions (HSIL), 20 invasive cervical cancers (ICC) and 125 atypical squamous cells of unknown significance (ASCUS). No statistically significant differences between cases and controls were found, regarding the influence of the R72P polymorphism with cytological classification, high risk-HPV infection and HPV16 presence (P = 0.336, P = 0.945, and P = 0.964, respectively). Also, the influence of this polymorphism in the median age of onset for LSIL, HSIL, and ICC was not statistically significant (P = 0.674, P = 0.810, and P = 0.928, respectively). Therefore, the hypothesis that women with Arg/Arg genotype have an increased risk of developing cervical cancer failed to be proven in this study. Moreover, our study reveals that results using exfoliated cervical cells are reliable as compared with studies on blood.