Small Cell Lung Cancer. Methodology and Preliminary Results of the SMALL CELL Study

Introduction: Small cell lung cancer (SCLC) is the most aggressive histologic type of lung cancer, and accounts for approximately 10%-15% of all cases. Few studies have analyzed the effect of residential radon. Our aim is to determine the risk factors of SCLC. Methods: We designed a multicenter, hospital-based case-control study with the participation of 11 hospitals in 4 autonomous communities. Results: Results of the first 113 cases have been analyzed, 63 of which included residential radon measurements. Median age at diagnosis was 63 years; 11% of cases were younger than 50 years of age; 22% were women; 57% had extended disease; and 95% were smokers or former smokers. Median residential radon concentration was 128 Bq/m(3). Concentrations higher than 40013q/m(3) were found in 8% of cases. The only remarkable difference by gender was the percentage of never smokers, which was higher in women compared to men (P<.001). Radon concentration was higher in patients with stage IV disease (non-significant difference) and in individuals diagnosed at 63 years of age or older (P=.032). Conclusions: A high percentage of SCLC cases are diagnosed early and there is a predominance of disseminated disease at diagnosis. Residential radon seems to play an important role on the onset of this disease, with some cases having very high indoor radon concentrations. (C) 2017 SEPAR. Published by Elsevier Espafia, S.L.U. All rights reserved.