Background and purpose: It has a significant effect for erlotinib on treatment of patients with epidermal growth factor receptor mutation in advanced non-small cell lung cancer (NSCLC). But almost all patients will eventually progress for the resistance of drug. This study was to evaluate the efficacy and safety of retreatment of erlotinib in patients with advanced NSCLC. Methods: It was a retrospective analysis of the 46 advanced NSCLC patients who previously treated with erlotinib and had clinical benefit. The patients were given erlotinib 150 mg orally once daily after failure to other medications until disease progression or the occurrence of intolerable toxicity. The clinical features

therapeutic effect and survival were analyzed. Results: The objective response rate of retreatment with erlotinib was 28.3%. The disease control rate was 60.9%. The rate of symptom relief was 45.7%. The median progression-free survival was 3.6 months. The median overall survival was 7.3 months. One-year survival rate was 8.7%. The median progression-free survival was significant longer in the patients who stopped taking erlotinib more than 6 months than those less than 6 months (P=0.002). The median overall survival was significant longer in the patients whose ECOG ≤2 than those ECOG 2 (P=0.038). The most common drug-related adverse events were rash and diarrhea. Conclusion: The retreatment of erlotinib could possibly prolong the survival time of patients who previously treated with erlotinib and had clinical benefit.