The Role of Gefitinib Treatment for Korean Never-Smokers with Advanced or Metastatic Adenocarcinoma of the Lung: A Prospective Study

Abstract

This prospective trial was conducted to evaluate the role of gefitinib in never-smokers with advanced or metastatic adenocarcinoma of the lung. The main inclusion criteria were stage IIIB/IV adenocarcinoma of the lung and status as a lifetime never-smoker. Patients received a 250-mg single oral daily dose of gefitinib until disease progression, unacceptable toxicity, or patient's refusal. Tumor response was assessed after every two 4-week cycles according to the World Health Organization response criteria. Additional analyses were performed to identify predictors of response and survival. Between August 2003 and March 2005, 72 Korean patients were enrolled; 55 chemotherapy naive, 17 previously treated; 6 male, 66 female; and ECOG PS 0/1/2, 24/42/4. All patients were assessed for response, toxicity, quality of life, and survival. Overall objective tumor response rate was 55.6% (95% confidence interval [CI], 43.4-67.3%). With a median follow-up of 23 months, the median survival time was 19.7 months (95% CI, 18.5-21.0 months) with a 1-year survival rate of 76.3%. The median duration of response was 6.8 months (95% CI, 4.7-9.0 months). Therapy-related improvement of symptoms and quality of life was observed within 2 to 4 weeks after the commencement of therapy in the responders. In a multivariate Cox proportional hazard model, good performance status and no prior history of chemotherapy were the two significant predictors of better survival (p = 0.005 and 0.042). Gefitinib showed very promising antitumor activity and survival outcome in Korean never-smokers with adenocarcinoma of the lung. It seems to be a good alternative to standard chemotherapy as a first-line therapy for this subgroup.