P53 codon 72 polymorphism and lung cancer risk: evidence from 27,958 subjects.
The role of p53 codon 72 polymorphism in the development of lung cancer remains obscure due to inconsistent findings of individual case-control studies published to date. A meta-analysis was conducted to better estimate the association between the p53 codon 72 variant and lung cancer risk. All relevant publications from the PubMed, Embase, Web of Science, and Wanfang databases were retrieved. Based on the inclusion criteria, 39 publications involving 44 independent case-control studies were finally included into this meta-analysis. Data were extracted and the pooled odds ratio (OR) with the corresponding 95 % confidence interval (95 % CI) was calculated. The overall pooled ORs showed no significant relationship of the p53 codon 72 polymorphism with increased or decreased risk of lung cancer in all gene contrast models (OR Pro vs. Arg = 1.04, 95 % CI = 0.96-1.13, P OR < 0.001; OR Pro/Pro vs. Arg/Arg = 1.07, 95 % CI = 0.91-1.25, P OR < 0.001; OR Arg/Pro vs. Arg/Arg =1.04, 95 % CI = 0.94-1.15, P OR < 0.001; OR Pro/Pro + Arg/Pro vs. Arg/Arg = 1.04, 95 % CI = 0.94-1.16, P OR < 0.001; OR Pro/Pro vs. Arg/Arg + Arg/Pro = 1.07, 95 % CI = 0.93-1.23, P OR < 0.001). According to the ethnicity, no significant association was observed in subgroup analyses of the Asians, Caucasians, Africans and the mixed population. Similar finding was found in subgroup analyses of hospital-based and population-based studies. Concerning the histological types of lung cancer, the p53 codon 72 variant exerts risk effect on the lung carcinogenesis in patients with adenocarcinoma (OR Arg/Pro vs. Arg/Arg = 1.10, 95 % CI = 1.00-1.22, P OR = 0.048). Additionally, subgroup analysis by the smoking status demonstrated that the p53 codon 72 variant seemed to play a protective role in lung carcinogenesis among the non-smokers but not the smokers in the contrast model of Arg/Pro vs. Arg/Arg (OR Arg/Pro vs. Arg/Arg = 0.71, 95 % CI = 0.50-1.00, P OR = 0.049). The present meta-analysis suggests the p53 codon 72 polymorphism may weakly modify the risk for lung cancer among the adenocarcinoma patients and non-smokers. Nevertheless, this association needs further confirmation in future studies with high quality.