Sequential Treatment of Advanced-stage Lung Adenocarcinoma Harboring Wild-type EGFR Gene: Second-line Pemetrexed Followed by Third-line Erlotinib versus the Reverse Sequence

Background: Pemetrexed and erlotinib represent novel agents for the treatment of non-small cell lung cancer (NSCLC). The role of sequential treatment in NSCLC has not been elucidated yet. We compared the efficacy of second-line pemetrexed followed by third-line erlotinib (P-E) to treatment with the reverse sequence (E-P). Patients and Methods: We analyzed data of 57 patients with advanced-stage (IIIB/IV) lung adenocarcinoma harboring wild-type epidermal growth factor receptor (EGFR) gene; 31 patients were treated with P-E and 26 patients with the E-P sequence. Results: The median progression-free survival (PFS) for patients treated with P-E was 3.6 months vs. 7.8 months for patients treated with E-P (p=0.029). The median overall survival (OS) for patients treated with P-E was 7.9 months vs. 26.3 months for patients treated with E-P (p=0.006). Conclusion: The results proved a significant improvement of both PFS and OS for patients treated with the E-P sequence as compared to the P-E sequence.