Racial and Ethnic Disparities in US Colorectal Cancer Mortality by County, Sex, and Age

In the past 2 decades, substantial declines in national colorectal cancer (CRC) mortality rates have been observed in the US; however, it is unclear whether these improvements have happened ubiquitously across geography, race and ethnicity, sex, and age group.

To assess variation in CRC mortality rates and changes over time, across county, race and ethnicity, sex, and age group (<45 years and ≥45 years).

This US population-based cross-sectional study used validated small-area estimation models to estimate county-level CRC mortality rates by race and ethnicity, sex, and age group from 2000 to 2019. Data analysis was completed in May 2023.

Estimates were stratified by county, race and ethnicity (American Indian or Alaska Native, Asian or Pacific Islander, Black, Hispanic or Latino, and White), sex (female and male), and age group (<45 years and ≥45 years) as reported on death certificates.

The outcome of interest was CRC mortality rates per 100 000 individuals. Estimates were corrected for race and ethnicity misclassification on death certificates and age standardized.

Among 3110 counties or combined county units with data from 2000 to 2019 (mean annual population, 306 million), most counties saw declines in CRC mortality among adults aged 45 years or older, from 82.5 (95% uncertainty interval [UI], 81.7 to 83.2) to 54.4 (95% UI, 53.9 to 54.9) deaths per 100 000 population among males and from 58.9 (95% UI, 58.4 to 59.3) to 39.7 (95% UI, 39.4 to 40.0) per 100 000 deaths among females 45 years or older. However, in 2019, considerable county-level variation, including within states, was observed. The largest county-level variation was observed among American Indian or Alaska Native males aged 45 years or older, ranging from 13.6 (95% UI, 8.2-20.8) to 213.5 (95% UI, 147.1-309.0) deaths per 100 000 population. Overall, 275 counties with unmasked estimates had CRC mortality rates of more than 100 deaths per 100 000 among at least 1 population (American Indian or Alaska Native females: 13 counties; American Indian or Alaska Native males: 92 counties; Black males: 182 counties; Hispanic or Latino males: 1 county; White males: 4 counties; all other populations: 0). CRC mortality rates among individuals aged younger than 45 years were stable or increased from 2000 to 2019.

This cross-sectional study found significant improvements in CRC mortality in adults aged 45 years or older at the national level and across all racial and ethnic populations between 2000 and 2019. However, CRC mortality rates remain extremely high in some counties and populations. These findings can help inform targeted intervention strategies for communities at highest risk.