Study Design
A retrospective, population-based, cohort study was conducted using the National Cancer Institute’s Survival, Epidemiology, and End Results Program (SEER) database. SEER collects population-based data on the incidence, prevalence, and survival of various cancers in the United States. It captures 28% of the US population, and is representative of its geographic, racial and ethnic diversity. Ethics approval for this study was waived by the Institutional Review Board.