Genetic variants in the ITGB6 gene is associated with the risk of radiation pneumonitis in lung cancer patients treated with thoracic radiation therapy.

The αvβ6 integrin is a cell surface adhesion molecule that plays critical roles in the injury and inflammation processes. We hypothesized that polymorphisms in αvβ6 integrin genes (ITGAV and ITGB6) might be associated with the risk of radiation pneumonitis (RP) in lung cancer patients treated with thoracic radiation. We genotyped three potentially functional αvβ6 integrin single-nucleotide polymorphisms (rs1839123 and rs4129787 in ITGAV, and rs4665162 in ITGB6) and found that the genotypes of rs4665162 single-nucleotide polymorphisms were predictors of RP development (for grade ≥2 RP, HR = 1.505, 95 % CI 1.069-2.119, P = 0.019; for grade ≥3 RP, HR = 3.006, 95 % CI 1.431-6.313, P = 0.004). Our results showed that AG/GG genotypes of ITGB6 rs4665162 gene were associated with a higher risk of RP in patients with lung cancer receiving radiotherapy and thus may serve as a reliable predictor of RP. Further studies will be needed to confirm these findings.