Purpose: The aim of this study is to assess if there is a relationship between residential radon and lung cancer histological types and patients' age at diagnosis.
Materials and methods: We conducted a multicenter hospital-based case-control study with eight participating hospitals. We included 216 never-smoking cases with primary lung cancer and 329 never-smoking controls. Controls were frequency matched with cases on age and sex distribution. Of them, 198 cases (91.7%) and 275 controls (83.5%) had residential radon measurements.
Results: Lung cancer risk reached statistical significance only for adenocarcinoma (Odds ratio [OR] 2.19; 95% Confidence interval [CI] 1.44-3.33), for other histologies the results were marginally significant. Residential radon level was higher for patients diagnosed before 50 and 60 years old than for older lung cancer cases.
Conclusions: Residential radon in never smokers seems to be a risk factor for all lung cancer histologies. Individuals diagnosed at a younger age have a higher residential radon concentration, suggesting an accumulative effect on lung cancer appearance.
Keywords: Lung neoplasms; case-control studies; histologic type; multicenter study; radon.