Author Contributions: Dr Sima had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Sima, Panageas, Schrag.
Acquisition of data: Sima, Schrag.
Analysis and interpretation of data: Sima, Panageas, Schrag.
Drafting of the manuscript: Sima, Panageas, Schrag.
Critical revision of the manuscript for important intellectual content: Sima, Panageas, Schrag.
Statistical analysis: Sima, Panageas.
Obtained funding: Schrag.
Study supervision: Sima, Schrag.
Financial Disclosures: None reported.
Funding/Support: This research was supported by grant R01 1147503 from the National Cancer Institute (Dr Schrag).
Role of the Sponsor: The funding organization had no role in the design and conduct of the study, in the the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.
Disclaimer: This study used the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database. The interpretation and reporting of these data are the sole responsibility of the authors.
Additional Contributions: We acknowledge the efforts of the Applied Research Program, National Cancer Institute; the Office of Research, Development, and Information, Centers for Medicare & Medicaid Services; Information Management Services; and the SEER Program tumor registries in the creation of the SEER-Medicare database.