TP53 polymorphisms and lung cancer risk: a systematic review and meta-analysis

To examine the risk of lung cancer associated with the codon 72, intron 6 and intron 3 TP53 polymorphisms a meta-analysis of published case-control studies was undertaken. The principle outcome measure was the odds ratio (OR) for the risk of lung cancer using homozygosity of the 'wild-type allele' as the reference group. Data from 13 studies detailing the relationship between lung cancer and the codon 72 polymorphism of TP53 and three studies examining the intron 3 and 6 polymorphisms of TP53 were analysed. The ORs of lung cancer associated with the Pro-Pro and Pro-carrier genotypes of codon 72 were 1.18 [95% confidence interval (CI) 0.99-1.41] and 1.02 (95% CI 0.86-1.20), respectively. The ORs of lung cancer associated with homozygous and variant allele carrier genotypes of the intron 6 (MspI RFLP) polymorphism were 1.13 (95% CI 0.55-2.27) and 1.30 (95% CI 0.75-2.26) and of the intron 3 (16 bp duplication) polymorphism were 1.50 (95% CI 0.76-2.97) and 1.11 (95% CI 0.53-2.35), respectively. Although polymorphic variations in TP53 represent attractive candidate susceptibility alleles for lung cancer the results from this analysis provide little support for this hypothesis. Additional well-designed studies based on sample sizes commensurate with the detection of small genotypic risks may allow a more definitive conclusion.