Comparing SEER and NCDB: a case study using colorectal cancer.

Nationwide datasets are frequently used to examine cancer trends and outcomes in the U.S. Understanding the strengths and limitations of the commonly used Surveillance, Epidemiology, and End Results (SEER) Program and the National Cancer Database (NCDB) is important when designing studies and interpreting results. We used colorectal cancer (CRC) as a case study to compare information available. We identified 575,128 (SEER) and 1,578,046 (NCDB) adults diagnosed with CRC between 2004 and 2021. The distribution of age, tumor location, stage, and treatment did not meaningfully differ between SEER and NCDB. SEER represents racially and ethnically diverse populations, including a higher proportion of Hispanic (11.7% vs 5.8%) and Asian/Pacific Islander (8.6% vs 3.3%) persons. SEER includes more information on area-level characteristics, such as county-level measures of poverty, unemployment, and migration and census tract-level measures of socioeconomic status. Age-adjusted incidence, mortality rates, and cause-specific survival are only available in SEER, facilitating detailed analyses of racial, ethnic, and socioeconomic differences in cancer incidence and mortality. NCDB provides information on tumor characteristics and treatment not available in SEER, including microsatellite instability, KRAS mutation, palliative treatment, unplanned readmissions, and 30-day mortality after surgery, facilitating analyses of treatment effectiveness and outcomes. Five-year overall survival was similar in SEER (55.6%) vs NCDB (57.5%).