Association between single nucleotide polymorphisms of the transforming growth factor β1 gene and the risk of severe radiation esophagitis in patients with lung cancer

Purpose: We investigated the association between single nucleotide polymorphisms (SNPs) in the transforming growth factor β1 (TGFβ1) gene and the risk of radiation-induced esophageal toxicity (RE) in patients with non-small-cell lung cancer (NSCLC). Methods and materials: Ninety-seven NSCLC patients with available genomic DNA samples and mostly treated with intensity modulated radio(chemo)therapy from 2003 to 2006 were used as a test dataset and 101 NSCLC patients treated with 3-dimensional conformal radio(chemo)therapy from 1998 to 2002 were used as a validation set. We genotyped three SNPs of the TGFβ1 gene (rs1800469:C-509T, rs1800471:G915C, and rs1982073:T869C) by the polymerase chain reaction restriction fragment length polymorphism method. Results: In the test dataset, the CT/TT genotypes of TGFβ1 rs1800469:C-509T were associated with a statistically significant higher risk of RE grade ⩾ 3 in univariate (P = 0.026) and multivariate analysis (P = 0.045) when compared with the CC genotype. These results were again observed in both univariate (P = 0.045) and multivariate (P = 0.023) analysis in the validation dataset. Conclusion: We found and validated that the TGFβ1 rs1800469:C-509T genotype is associated with severe RE. This response marker may be used for guiding therapy intensity in an individual patient, which would further the goal of individualized therapy.