Background: Gefitinib, a selective inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, has been approved effective in local advanced or metastatic non-small cell lung cancer (NSCLC), with the equivalent response rate to that of chemotherapy in Asian patients. Asian ethnicity, gender, smoking history, adenocarcinoma histology were remarkably associated with gefitinib response and survival. However, predictive factors of gefitinib response and survival are still unclear in Asian population. In this study, we retrospectively reviewed the data of 153 Chinese NSCLC patients who received a single agent of gefitinib with the purpose of identifying the potential predictive factors of gefitinib response and survival.
Methods: Tumor response, survival and the clinicopathologic factors of 153 NSCLC patients treated between November of 2003 and June of 2004 were collected retrospectively from the multicenter clinical trial in China. Pearson Chi-square test and Logistic regression test were performed respectively as univariate and multivariate analyses of gefitinib response. Overall survivals between groups with different predictive factors were compared by log-rank tests. Multivariate analysis was performed to identify factors that independently predict for survival.
Results: A total of 153 patients were included in this analysis. Objective response rate was statistically significant higher in patients with younger age (≤65 years) and longer interval from diagnosis to gefitinib treatment (≥6 months) in multivariate analysis (P < 0.05). The median follow-up duration was 10.0 months (0.5-16.8). The median survival was 10.3 months (95% CI: 8.1-12.6) and 1-year survival was 44.1%. Significant independent predictive factors associated with longer survival in multivariate analysis were good performance status (score 0-1), controlled disease (CR+PR+SD) to most recent chemotherapy and controlled disease to gefitinib (P < 0.05).
Conclusions: Gefitinib is effective in local advanced or metastatic NSCLC patients who failed to chemotherapy in Chinese population. In Chinese NSCLC population, younger age (≤65 years) and longer interval from diagnosis to gefitinib treatment (≥6 months) were predictive factors in multivariate analysis for gefitinib response; good performance status (score 0-1), controlled disease to most recent chemotherapy and controlled disease to gefitinib were independent prognostic factors for survival.