Asian ethnicity as a predictor of response in patients with non-small-cell lung cancer treated with gefitinib on an Expanded Access Program

Background: The primary objective of this retrospective study was to investigate the potential role of East Asian ethnicity or origin in predicting response to gefitinib in advanced-stage non-small-cell lung cancer (NSCLC). Patients and methods: A chart review was done of all patients treated with gefitinib at M. D. Anderson Cancer Center on the Expanded Access Program. Results: There were 223 patients with advanced-stage NSCLC who were enrolled. Of these, 182 received ≥ 1 dose, and 160 were evaluable for response. The partial response rate was 8.8%, and the stable disease rate was 26.3%. Median time to progression was 2.5 months, and median survival was 6.8 months. The 1- and 2-year survival rates were 35.3% and 12.4%, respectively. Partial responses were seen in 7 of 12 patients (58.3%) of East Asian origin compared with 7 of 131 patients who were white (5.3%). This difference was statistically significant when controlling for histology, smoking status, hemoglobin, and diarrhea. Never smoking and diarrhea were also independent predictors of response. Conclusion: For the first time, in a multivariate analysis, we observed a positive relationship between East Asian origin and response to gefitinib. These findings might help determine which patients will likely benefit from gefitinib.