1. Data source

We analyzed incidence, survival, and treatment data from the SEER program of the National Cancer Institute from the years 2004 to 2011. We specifically examined the SEER 18 registries because they were continuously active for the duration (2004 to 2011). The SEER 18 registries report specific data on patient demographics, primary tumor site, tumor morphology, stage at diagnosis, first course of treatment, and follow-up for vital status (outcome/survival). The SEER 18 registries were purposefully selected to maximize generalizability to the overall United States population. Specifically, these 18 registries capture about 28% of the entire United States population [⁹].