Breast cancer mortality by age and race and/or ethnicity across counties in the United States, 2000-2019.

BACKGROUND

We evaluated county-level variations in racial and/or ethnic disparities in breast cancer mortality rates across the United States over a 20-year period.

METHODS

Validated small-area estimation models were used to calculate breast cancer mortality rates by age and race and/or ethnicity among females across all United States counties from 2000 to 2019. The estimates were corrected for misreporting of race and/or ethnicity on death certificates and age-standardized to the 2010 United States Census.

RESULTS

Age-standardized national breast cancer mortality rates declined between 2000 and 2019, from 33.6 (95% uncertainty interval = 33.4-33.9) to 24.8 (24.6-25.0) deaths per 100 000 females. However, there were variations in breast cancer mortality rates across racial and/or ethnic populations at the county level. For instance, 243 of 1478 counties showed increasing breast cancer mortality rates from 2000 to 2019 among Latina females aged <50 years (absolute increase [median] = 0.23 deaths per 100 000; maximum = 1.0). County-level patterns for American Indian/Alaska Native females aged 50-74 years showed increasing breast cancer mortality rates across 108 of 474 counties (median = 4.4 per 100 000; max = 17.5). The largest county-level increases were seen among American Indian/Alaska Native (184 of 474 counties; median = 15.2 per 100 000; max = 124.0) and Asian (589 of 667 counties; median = 14.1 per 100 000, max = 41.0) females aged 75+ years.

CONCLUSIONS

Despite a substantial decrease in overall breast cancer mortality rates across all female populations combined in the United States, there were significant county-level variations in breast cancer mortality rates by race and/or ethnicity.