How representative are the surveillance, epidemiology, and end results (SEER) Program cancer data of the United States?

Objective: Data from the 11 Surveillance, Epidemiology, and End Results tumor registries cover 14% of the US population and are often used to provide national estimates of cancer incidence and survival. Cancer mortality data for the US and for SEER are compared to assess the representation of SEER to the US. Methods: Comparisons between US and SEER cancer mortality were made for 16 of the leading causes of cancer death. Cancer site-specific comparisons were also made by race and sex. In addition, tobacco-related cancers were considered. Analyses were performed for the years when all 11 SEER registries were included in the SEER program. Poisson regression was used to estimate site-specific cancer mortality rate ratios between the US and SEER. Results: Cancer site-specific mortality rates derived from SEER data tend to under-represent the US cancer mortality experience for white males and females and black males. Under-representation is observed across the majority of SEER registries, with the highest amount of under representation in Utah and New Mexico. Under-representation of SEER data compared with US data is noticeably greater among tobacco-related cancers, particularly in Utah and New Mexico. Conclusion: For certain cancer sites, particularly tobacco-related cancers, the SEER coverage population is not representative of the US population.