2.1. Data Source

The source of data for this study was from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute in the United States. SEER is a program that collects and publishes cancer incidence, treatment, and survival data from population-based cancer registries, representing approximately 28% of the US population [8]. The 18 registries in SEER-18 include approximately 25% of White population, 26% of Black population, 38% of Hispanic population, 44% of American Indians and Alaska (A/PI) population, 50% of Asians, and 67% of Hawaiian/Pacific Islanders [8]. These 18 SEER registries include Atlanta, Detroit, Greater California, Greater Georgia, Hawaii, Iowa, Kentucky, Los Angeles, New Mexico, New Jersey, Rural Georgia, Connecticut, San Francisco-Oakland, Seattle-Puget Sound, San Jose-Monterey, the Alaska Native Tumor Registry, Louisiana, and Utah.