Improving Survival for Stage IV Non-small Cell Lung Cancer: A Surveillance, Epidemiology, and End Results Survey from 1990 to 2005

BackgroundAlthough there has been a significant survival improvement for patients with metastatic NSCLC enrolled in randomized trials, it is not clear whether a similar benefit is seen in an unselected group of patients. Therefore, we conducted a study to evaluate for survival changes in a large national cancer registry database.Patients and MethodsThe Surveillance, Epidemiology, and End Results (SEER) registry was queried for patients with NSCLC stage IV, aged 21 years or older, and diagnosed between 1990 and 2005. We analyzed four equally divided time periods between 1990 and 2005 (1990 to 1993 or period 1, 1994 to 1997 or period 2, 1998 to 2001 or period 3, and 2002 to 2005 or period 4) to determine changes in overall survival for all patients and according to histology.ResultsWe identified 129,337 patients meeting eligibility criteria. There was a significant improvement in overall survival since period 1. One-year and 2-year overall survival increased from 13.2 and 4.5%, respectively, in period 1 to 19.4% and 7.8%, respectively, in period 4. On multivariate analysis, survival for adenocarcinoma was increased compared with squamous cell carcinoma only in period 4 (p = 0.02).ConclusionsThere has been a modest but statistically significant improvement in overall survival for stage IV NSCLC over the past 16 years. The recent differences in outcomes based on histology observed in period 4 may reflect the increased activity of epidermal growth factor receptor tyrosine kinase inhibitors in adenocarcinoma compared with squamous cell carcinoma.