Lung cancer and residential radon in never-smokers: A pooling study in the Northwest of Spain

Abstract

BackgroundUsing a pooled case-control study design, including only never-smokers, we have assessed the association of residential radon exposure with the subsequent occurrence of lung cancer. We also investigated whether residential radon poses a different risk specifically for adenocarcinoma. MethodsWe pooled individual data from different case-control studies conducted in recent years in Northwestern Spain which investigated residential radon and lung cancer. All participants were never-smokers. Cases had a confirmed biopsy of primary lung cancer. Hospital controls were selected at pre-surgery units, presenting for non-complex surgical procedures. They were interviewed using a standardized instrument. Residential radon was measured using alpha track detectors at the Galician Radon Laboratory at the University of Santiago de Compostela. ResultsA total of 1415 individuals, 523 cases and 892 controls were included. We observed an odds ratio of 1.73 (95%CI: 1.27–2.35) for individuals exposed to ≥ 200 Bq/m3 compared with those exposed to ≤100 Bq/m3. Lung cancer risk for adenocarcinoma was 1.52 (95%CI: 1.14–2.02) using the same categories for radon exposure. ConclusionsResidential radon is a clear risk factor for lung cancer in never-smokers. Our data suggest that radon exposure is associated with all histological types of lung cancer and also with adenocarcinoma, which is currently the most frequent histological type for this disease.