Abstract
BACKGROUND: Colorectal cancer (CRC) incidence rates have been decreasing in the United States (US), but there is limited information about differences in these improvements among individuals from different racial and ethnic subgroups across different regions of the US. METHODS: Data from the National Program of Cancer Registries (NPCR) and the Surveillance, Epidemiology, and End Results (SEER) databases were used to examine trends in CRC incidence from 2001 to 2020 using a population-based retrospective cohort study. We obtained annual estimates of CRC incidence and used meta-regression analyses via weighted linear models to identify main effects and interactions that explained differences in CRC incidence trends among groups defined by race/ethnicity and US region while also considering CRC stage and sex. To summarize overall trends over time in incidence rates for specific racial and ethnic groups within and across US regions, we obtained average annual percentage change (AAPC) estimates. RESULTS: The greatest differences in CRC incidence trends were among groups defined by race/ethnicity and US region. Non-Hispanic Black (NHB) persons had the largest declines in CRC incidence, with AAPC estimates ranging from -2.27 (95% CI: -2.49 to -2.06) in the South to -3.03 (95% CI: -3.59 to -2.47) in the West, but had higher-than-average incidence rates at study end. The AAPC estimate for American Indian/Alaska Native (AIAN) persons suggested no significant change over time (AAPC: -0.41, 95% CI: -2.51 to 1.73). CONCLUSION: CRC incidence trends differ among racial/ethnic groups residing in different US regions. Notably, CRC incidence rates have not changed noticeably for AIAN persons from 2001-2020. These findings highlight the importance of reinvigorating collaborative efforts to develop geographic and population-specific screening and preventative approaches to reduce the CRC burden experienced by Native American communities and members of other minoritized groups.