P5372(RP ) polymorphism in head and neck cancer: an association and meta-analysis study

Abstract

Head and neck cancer occur in the oral cavity, pharynx (oropharynx, nasopharynx, and hipopharynx) and larynx. Extensive epidemiologic studies have revealed that chronic tobacco smoking and alcohol consumption are the two main risk factors associated with the multifactorial etiology of head and neck cancer, followed by nutritional factors, HPV infection, and genetic polymorphism. A frequently studied polymorphism in Squamous Cell Carcinoma (SCC) of head and neck is a G-to-C Single Nucleotide Polymorphism(SNP) at codon 72 in p53 gene, which codes for Arginine or Proline (Arg or Pro) in P53 protein. This study aimed at investigating the distribution and potential association of this SNP in SCC. In this study, 602 participants were assessed: 331 cases of head and neck SCC from
Araújo Jorge Hospital (experimental group) and 271 healthy individuals randomly selected among the population of Goiânia, state of Goiás (Brazil) (control group). The samples were processed, DNA was isolated and subsequently used for PCR amplification and molecular evaluation of p5372 gene polymorphism. Additionally, a meta-analysis was carried out using 29 relevant case-control studies of p5372 SNP genotyping in SCC of head and neck. The allelic frequencies of p53Arg and p53Pro in all participants were, respectively, 73.3% and 27.7% in the experimental group and 74.2% and 25.8% in the control group (p = 0.119).  Genotypic frequencies were 56.8% Arg/Arg, 32.9% Arg/Pro, and 10.3% Pro/Pro
in the experimental group and 61.3% Arg/Arg, 25.8% Arg/Pro, and 12.9% Pro/Pro in the control group (p = 0.137). According to the current data and the meta-analysis, no association between p5372 SNP and the risk to develop SCC of head and neck was found. On the other hand, after stratifying data according to the anatomical site, we observed that the homozygous genotype Arg/Arg is an important oncogenic risk factor associated with oropharynx carcinoma.