PURPOSE:The epidermal growth factor receptor inhibitors, gefitinib and erlotinib, are used as standard salvage therapy for advanced non-small-cell lung cancer (NSCLC). The aim of the present study was to compare their efficacies in this population. PATIENTS AND METHODS:The Taiwan Cancer Registry and the National Health Insurance claim databases were searched for newly diagnosed patients with NSCLC from 2004 to 2007 who received gefitinib or erlotinib as third-line therapy. Overall survival (OS) and time to treatment failure (TTF) were determined from registered parameters. Treatment efficacies were compared by the log-rank test in total population and subsets with different clinical characteristics. The Cox's proportion hazard model was used to estimate the adjusted hazard ratios in multivariate analyses. RESULTS:A total of 984 patients who received gefitinib (67%) or erlotinib (33%) were included. Patients receiving gefitinib or erlotinib had similar OS (median, 10.2 versus 9.9 months, p=0.524) and TTF (median, 5.5 versus 3.4 months, p=0.103). In multivariate analyses, both treatment groups had similar risk of overall mortality (adjusted hazard ratio [HR]=1.04, p=0.629) and treatment failure (adjusted HR=0.94, p=0.417). Comparing the treatments in subgroups based on age, tumour histology and gender also revealed no differences in OS and TTF. For patients who received gefitinib or erlotinib for more than 3 or 6 months, there was no difference in TTF but patients who received erlotinib had longer OS. CONCLUSIONS:Gefitinib and erlotinib had similar efficacies as salvage therapy for advanced NSCLC in Taiwan.