Race was categorized as white, black, Hispanic, and others (which included Asian American, American Indian, and other), whereas sex was categorized as male and female. Age at diagnosis was a continuous variable for purposes of analysis. Primary payer or insurance type at diagnosis was determined using Facility Oncology Registry Data Standards (FORDS)7 codes, which were grouped into the following categories: Medicaid, Medicare (which included both Medicare alone and Medicare with supplement), uninsured (which included FORDS codes for not insured– NOS; not insured–charity write-off, and not insured–self-pay), other government funded plans (VA, Indian Health Service, Public Health Service, welfare, state-funded–NOS, and federally funded–NOS), and private insurance plans (health maintenance organization, preferred provider organization, managed care–NOS, private insurance, Champus or Tricare, military, and insured–NOS). The plans in the private insurance category were grouped together because these plans represent either privately purchased insurance (purchased by the individual, a family member, and/or employer) or insurance provided by the military that functions in a similar manner as private insurance (Champus or Tricare). Because Medicare eligibility for individuals younger than 65 years differs from eligibility for those 65 years or older, the Medicare category was dichotomized for analyses into Medicare among patients 18 to 64 years of age and Medicare among patients 65 years or older.