The EGFR mutation and its correlation with response of gefitinib in previously treated Chinese patients with advanced non-small-cell lung cancer

Background: The aim of the study was to evaluate the efficacy of gefitinib and the epidermal growth factor receptor (EGFR) mutation to gefitinib response in a series of Chinese patients with pretreated advanced non-small-cell lung cancer (NSCLC). Methods: A total of 98 patients who had failed at least one platinum-based regimen received gefitinib 250 mg once daily. The mutation analysis of the EGFR kinase domain was performed for 30 patients using paraffin-embedded tumor tissue. Results: The response rate was 31.6% and the disease control rate was 67.3%. Objective response was correlated with adenocarcinoma, female gender and non-smokers. Median progress free survival (PFS) was 7.0 months, median overall survival (OS) was 12.0 months and 1-year survival was 53.1%. The median PFS and OS were improved among patients with adenocarcinoma, gefitinib responders and non-smokers. Active gene mutation was detected in 12 patients. Mutation rates were higher among gefitinib responders, non-smokers, patients with adenocarcinoma and female patients. OS was longer for patients with gene mutation than for patients without mutation. Conclusion: Gefitinib demonstrated significant antitumor activity with a favorable toxicity profile for pretreated Chinese patients with advanced NSCLC. The active mutation of the EGFR kinase domain was strongly associated with response to gefitinib and prolonged overall survival.