Small-Cell Lung Cancer in Never-Smokers: A Case Series With Information on Family History of Cancer and Environmental Tobacco Smoke

Small-cell lung cancer (SCLC) is closely associated with smoking, but there has been little attention given to never-smokers. The potential causative factors of a family history of cancers (FHC) and environmental tobacco smoke (ETS) have not been described in previous reports. We retrospectively reviewed the clinical files of 271 consecutive SCLC patients who were newly diagnosed in Kinki-Chuo Chest Medical Center, Japan, from January 2004 through July 2010, and identified four cases (1.5%) who were never-smokers. They were all females and had an FHC with exposure to ETS. One patient had both epidermal growth factor receptor (EGFR) and K-ras mutations. FHC and ETS provide a potential clue to clarify the development of SCLC in never-smokers. Further research will be needed to better understand the potential role of molecular alterations in the pathogenesis of small-cell carcinoma.