Data Sources

Incidence Data

The primary source of data on cancer incidence is medical records. Staff at health care facilities abstract data from patients’ medical records, enter it into the facility’s own cancer registry if it has one, and then send the data to the regional or state registry. Other data sources include physicians’ offices, radiation facilities, freestanding surgical centers, and pathology laboratories.

Mortality Data

Cancer mortality statistics are based on information from all death certificates filed in the 50 states, the District of Columbia, and Puerto Rico, and processed by the National Vital Statistics System.

Population Denominator Data

The population estimates for the denominators of incidence and death rates are race-specific, ethnicity-specific, and sex-specific county population estimates aggregated to the state or metropolitan-area level.

Population estimates used in the calculation of Puerto Rico incidence and death rates are sex-specific, are obtained from the U.S. Census Bureau, and are not available by race or ethnicity. To account for the population shift that occurred due to Hurricane Maria, the population denominators for 2017 were adjusted by dividing the U.S. Census Bureau’s July 1, 2017 (vintage 2018) Puerto Rico population estimate in half.