The Association between TGF-β1 Polymorphisms and Radiation Pneumonia in Lung Cancer Patients Treated with Definitive Radiotherapy: A Meta-Analysis

BACKGROUND Previous studies investigating the association between TGF-β1 polymorphisms and Radiation Pneumonia (RP) risk have provided inconsistent results. The aim of our study was to assess the association between the TGF-β1 genes C509T, G915C and T869C polymorphisms and risk of RP in lung cancer patients treated with definitive radiotherapy. METHODS Two investigators independently searched the Medline, Embase, CNKI, and Chinese Biomedicine Databases for studies published before September 2013. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for TGF-β1 polymorphisms and RP were calculated in a fixed-effects model or a random-effects model when appropriate. RESULTS Ultimately, each 7 studies were found to be eligible for meta-analyses of C509T, G915C and T869C, respectively. Our analysis suggested that the variant genotypes of T869C were associated with a significantly increased RP risk in dominant model (OR = 0.59, 95% CI = 0.45-0.79) and CT vs. TT model (OR = 0.47, 95% CI = 0.32-0.69). In the subgroup analyses by ethnicity/country, a significantly increased risk was observed among Caucasians. For C509T and G915C polymorphism, no obvious associations were found for all genetic models. CONCLUSION This meta-analysis suggests that T869C polymorphism of TGF-β1 may be associated with RP risk only in Caucasians, and there may be no association between C509T and G915C polymorphism and RP risk.