How generalizable are the SEER registries to the cancer populations of the USA?

Overall, SEER registries were not significantly different from non-SEER areas in terms of average age-race-specific proportions of late-stage BC or CRC, except for estimates of late-stage CRC for other race and young Asian and Hispanic women. Although case completeness was better in SEER areas than non-SEER areas, SEER areas had greater economic disadvantage and greater minority diversity among the population. This study demonstrated a need for caution in using SEER data and discussed advantages of using the more complete USCS database.