Improving survival for metastatic non-small cell lung cancer: A SEER database analysis from 1990 to 2005

Abstract

8078 Background: Treatment of metastatic non-small cell lung cancer (NSCLC) has evolved over the last decade with the increased use of third-generation chemotherapy agents, established benefits from second-line chemotherapy, and the development of targeted agents. We conducted a study to evaluate whether these treatment advances translated into improved survival in a large registry database. Methods: The Surveillance Epidemiology and End Results (SEER) registry was queried for patients with NSCLC stage IV, aged 21 or older, and diagnosed between 1990 and 2005. Overall Survival (OS) rates were estimated by the Kaplan-Meier method and compared using log-rank test. Cox proportional hazard model was fitted to evaluate whether the diagnostic period is an independent predictor for OS. Demographic variables included period of diagnosis (1990–1993 or P1, 1994–1997 or P2, 1998–2001 or P3, and 2002–2005 or P4), age, gender, race, and histology. Results: There were 127,816 patients meeting eligibility criteria. Median age at presentation was 67 and most patients were male (58%), white (81%), and had adenocarcinoma (39%). Although there was no significant differences in OS between periods 1 and 2 (p = 0.18), there was a significant improvement from periods 2 to 3 (p < 0.001) and 3 to 4 (p < 0.001). 1-y and 2-y OS increased from 13.2% and 4.5% respectively in P1 to 19.4% and 7.8% respectively in P4. Predictive factors for improved survival in multivariate analyses included diagnostic period (p < 0.001), younger age (p < 0.0001), female gender (p < 0.0001), and non-black race (p < 0.0001). After adjusting for demographic factors, there were no significant differences in OS between adenocarcinoma and squamous cell from P1 to P3 (1990–2001). However, P4 showed a significant increase in OS for adenocarcinoma compared with squamous cell (p = 0.02). Conclusions: There has been a significant improvement in OS for stage IV NSCLC over the last 8 years. The recent differences in outcomes based on histology observed in P4 may reflect the increased activity of newer therapies in adenocarcinoma compared with squamous cell, including gefitinib and erlotinib. No significant financial relationships to disclose.