Trends in early onset colorectal cancer–related mortality among adults in the United States from 1999-2020.

42 Background: Colorectal cancer (CRC) has witnessed a decrease in incidence and mortality in the United States (US) for the past few decades likely due to increased screening and improvements in treatment . Despite the overall burden of CRC has declined and survival has been made for older adults, there is a simultaneous and alarming increase in CRCs diagnosed in individuals younger than 50 years of age. These Early Onset CRC (EOCRC) which now account for roughly 10% of new CRC cases in the US. The purpose of this study was to assess the trends and regional differences in EOCRC-related mortality among adults in the United States. Methods: Death certificates from the CDC WONDER (Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research) database were examined from 1999 to 2020 for -related mortality in adults <45 years of age. Age-adjusted mortality rates (AAMRs) per 10,000 persons and annual percent change (APC) were calculated and stratified by year, sex, race/ethnicity, and geographic region. Results: Between 1999 and 2020, 32,850 EOCRC-related deaths occurred among adults 25-44 years. The AAMR increased from 2.1 in 1999 to 2.6 in 2020. Men had consistently higher AAMR than women from 1999 (AAMR men: 2.0 vs women: 1.6) to 2020 (AAMR men: 2.6 vs women: 2.0). Non Hispanic (NH) African Americans had the highest overall AAMR (3.1), followed NH White (2.2), NH Asians (1.6) and Hispanics (AAMR 1.5) Caucasians have had a significant increase in mortality over the past 2 decades ( APC 1.4 (95%Cl 1.1-.7)) whereas the Hispanics have shown an APC of 4 (95% Cl 2.3-5.8 from 2012-2020). AAMR also varied substantially by region (overall AAMR: Midwest 2.1; South: 2.4; West: 1.9; Northeast: 2.0). States in the top 90th percentile of EOCRC-related AAMR were Mississippi, Arkansas, Oklahoma, South Carolina, Alabama West Virginia, Louisiana ,Kentucky and Tennessee which had approximately double the AAMRs compared with states that fell into the lower 10th percentile. Conclusions: EOCRC-related mortality in U.S. adults has been steadily increasing over the past two decades . The highest AAMRs were observed among African American adults and men, and among patients living in the Southern , Midwestern regions and those living in the nonmetropolitan United States. Targeted strategies are needed to prevent and treat EOCRC among older adults to curb increasing levels of EOCRC-related mortality.