Systematic Review of Brain Metastases in Patients With Non–Small-Cell Lung Cancer in the United States, European Union, and Japan
Brain metastases (BRM) occur frequently in non–small-cell lung cancer (NSCLC) and present a substantial unmet medical need. Previous literature on global BRM prevalence, treatment patterns, costs, and outcomes typically has described a subset of these factors. The primary objective of this systematic literature review was to summarize BRM-related epidemiology, treatment patterns, costs, and survival of patients with NSCLC in the United States, European Union, and Japan. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards. Literature searches were conducted in PubMed, Ovid MedLine, and Embase to identify studies published between 2003 and 2014. Peer-reviewed, English language, and human observational studies of patients with NSCLC and BRM were identified. Demographic characteristics, treatment patterns, histology subtype, costs, and survival data were extracted into Microsoft Excel and descriptively analyzed using SAS version 9.2 (SAS Institute, Inc). Of 8257 studies, 243 were eligible. Data from 46,422 patients with NSCLC and 27,907 patients with BRM were summarized. Radiation therapy was used by 70.7% (n = 19,736) of the total BRM population, followed by systemic therapy (8.9%, n = 2497), and surgery (6.1%, n = 1690). Reported median survival was 9.78 months ranging from 2.5 to 38 months. Radiation therapy had the best outcome at 10.0 months with 41.6% (n = 101) of the studies reporting the use of stereotactic radiosurgery. Highly variable median survival and treatment patterns were reported between countries. Costs and histology subtype data were not reported for most countries, highlighting the need for additional research to describe the economic burden of BRM and improve the diagnosis, prognosis, and prescription of effective therapies.