LAUSR

Abstract Background Small-cell lung cancer (SCLC) is known to be closely associated with smoking; therefore, never-smokers with SCLC are very rare. We conducted a retrospective study to investigate the clinicopathological features of SCLC in never-smokers. Methods We reviewed the medical charts of SCLC patients treated at our institution from December 2000 to May 2016, and identified SCLCs in never-smokers. We collected the clinicopathological data, treatment regimen, and efficacy and survival data. In addition, we compared these data with those of SCLCs in smokers. The EGFR mutations were examined in available samples of SCLCs in never-smokers. Results A total of 196 SCLC patients were reviewed, and 8 never-smokers were identified (4.1%). All of them had de novo SCLC. The median age was 71 years (range: 66–84 years), and 6 patients were female (75%). Seven patients (88%) had been exposed to environmental tobacco smoke (ETS), and the other patient was an atomic bomb survivor. Only 1 patient had an EGFR mutation (13%). The overall response rate (ORR) to anticancer treatments was 88%. The median progression-free survival (PFS) was 6.1 months (95% confidence interval: 2.6-infinity), and the median overall survival (OS) was 74.6 months (95% confidence interval: 4.8-infinity). No marked differences were found in the ORR or PFS between never-smokers and smokers. However, the OS of never-smokers was statistically longer than that of smokers (median: 17.3 months, p =0.0371). Conclusion The prognosis of SCLC in never-smokers was relatively favorable. Never-smoker SCLC with EGFR mutations was relatively rare in our population.