Gefitinib as first-line treatment for patients with NSCLC with activating EGFR mutationin exons 19 (Del19) or 21 (L858R) in the Czech Republic

Aims: This study evaluates treatment outcomes in 161 NSCLC patients from Czech Republic according to mutations located in exons 19 (Del19) and 21 (L858R). Methods: Patients were treated with gefitinib in first line between 02/2010 and 12/2014 in 10 institutions. Retrospective analyses were carried out to assess the effectiveness and safety of treatment according to mutations Del 19 and L858R. Results: Out of 161 patients, 105 had Del19, and 56 L858R mutation. Between these two groups there was not statistically significant difference in sex (p=0.727), age (p=0.204), in smoking status (p=0.354) and according to performance status (p=0.547).There was statistically borderline significant difference in adenocarcinoma proportion (p=0.045). In the group with Del19 were 96% patients with adenocarcinoma and 85% in the group with L858R. There was not statistically significant difference according to disease control (p=0.479) and according the response (p=0.052). There was not statistically significant difference in OS (p=0.390); in the group of patients with Del19 was 22.7 months (CI 95%: 17.7; 27.8), in the group with L858ROS was 16.3 months (CI 95%:10.8; 21.8), but 70% patients still alive. Without the statistical significance was the difference in PFS; in the group of patients with Del19 it was 11,0 months (CI 95%:9.1; 12.8) and in the group with L8538R it was 9.4 months (CI 95% 6.6; 12.2). SimiIar numbers of adverse effects were observed in either group (35,2% and 35.7%). Conclusion: The treatment with gefitinib was very safe and PFS and OS were satisfactory without statistically significant differences acoording Del19 and L858R mutations.