Combined survival analysis of prospective clinical trials of gefitinib for non-small cell lung cancer with EGFR mutations.

Abstract

Somatic mutations of the epidermal growth factor receptor (EGFR) gene are associated with an increased response to gefitinib in patients with non-small cell lung cancer. We have examined the impact of gefitinib on progression-free survival and overall survival in patients with EGFR mutation-positive non-small cell lung cancer. We searched for all clinical trials that prospectively evaluated the efficacy of gefitinib for advanced non-small cell lung cancer with EGFR mutations in Japan. We did a combined analysis based on individual patient data from the identified trials. Seven eligible trials were identified for a total of 148 non-small cell lung cancer patients with EGFR mutations. The overall response rate to gefitinib was 76.4% [95% confidence interval (95% CI), 69.5-83.2]. The median progression-free survival and overall survival were 9.7 months (95% CI, 8.2-11.1) and 24.3 months (95% CI, 19.8-28.2), respectively. Good performance status and chemotherapy-naïve status were significantly associated with a longer progression-free survival or overall survival. Of the 148 patients, 87 received gefitinib as a first-line therapy, whereas 61 received systemic chemotherapy before gefitinib treatment. The median progression-free survival after the start of first-line therapy was significantly longer in the gefitinib-first group than in the chemotherapy-first group (10.7 versus 6.0 months; P < 0.001), whereas no significant difference in median overall survival was apparent between the two groups (27.7 versus 25.7 months; P = 0.782). Gefitinib monotherapy confers substantial clinical benefit in terms of progression-free survival and overall survival in non-small cell lung cancer patients with EGFR mutations. Randomized trials comparing chemotherapy with gefitinib as a first-line treatment are warranted in such patients.