Shifting Trends in Early-Onset Colorectal Cancer in South Dakota: A Focus on Population Incidence Patterns

Early-onset colorectal cancer (EOCRC) is rising nationally, with South Dakota experiencing a reversal in historical trends. Traditionally, American Indian populations have had higher EOCRC rates attributed to healthcare access disparities and socioeconomic factors. Recent data now reveals that the White population exhibits higher EOCRC incidence in South Dakota.

We analyzed data from the South Dakota Cancer Registry (2007-2022) to calculate EOCRC incidence rates for American Indian and White populations. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were computed. Behavioral risk factors and insurance coverage were also reviewed.

The White population's EOCRC incidence rose to 9.6 per 100,000 in 2018-2022, surpassing the American Indian rate of 7.8 per 100,000 (IRR = 1.27, 95% CI: 1.10-1.45). From 2021 to 2022, insurance coverage improved for both American Indians (46.6% to 55.5%) and Whites (81.5% to 83.4%). However, lifestyle disparities persisted. In 2021, American Indians reported higher fruit but lower vegetable intake than Whites. In 2022, physical activity was lower among American Indians (63.3%) than Whites (77.8%). In 2022-2023, obesity prevalence was significantly higher among American Indians (50.2%) than Whites (34.7%). Binge and heavy drinking percentages were elevated among Whites (30.8% and 10.1%, respectively) compared to American Indians (20.0% and 5.4%). Commercial tobacco use was reported higher among American Indians (45.1%) when compared to Whites (27.0%).

This shift highlights the success of American Indian-focused interventions and underscores emerging challenges among the White population.