Residential radon,EGFRmutations andALKalterations in never-smoking lung cancer cases

The aim of this study was to assess if residential radon exposure might causeEGFRmutations orALKrearrangements in never-smokers. We designed a multicentre case–control study in a radon-prone area (Galicia, Spain); only lung cancer cases were included in the study. We obtained residential radon measurements and clinical information for all the participants. We compared the median values of residential radon between patients withEGFRmutations orALKrearrangementsversusthose without them. 323 patients were included. Median age was 70 years and 19.5% were males. 42 and 15% of patients wereEGFR- andALK-positive, respectively. The most frequentEGFRalterations were exon 19 deletions and exon 21 (L858R) single-point substitution mutations.ALK-positive patients were 10 years younger thanALK-negative patients. Residential radon levels were two-fold higher in patients with exon 19 deletions compared with patients with exon 21 (L858R) single-point substitution mutations (216versus118 Bq·m−3; p=0.057). There were no differences in residential radon levels byEGFRmutation status.ALK-positive patients (n=12) essentially had two-fold residential radon levels compared withALK-negative patients (290versus164 Bq·m−3, respectively). Residential radon may have a role in the molecular signature of lung cancer in never-smokers, although more studies with larger sample sizes are needed to support this hypothesis.