(337) Evaluating Early-Onset Colorectal Cancer Incidence Trends and Geographic Disparities Among Adults Aged 20–50 in Michigan

Background: : Early-onset colorectal cancer (EOCRC), defined as a diagnosis before age 50, represents a growing public health challenge. National incidence rates for adults aged 20–49 have nearly doubled in recent decades. Despite these trends, current colorectal cancer screening guidelines begin at age 45, potentially missing at-risk individuals under 45. Over 60% of EOCRC cases are present at advanced stages, resulting in higher treatment costs and worse prognosis.

Objective: : To evaluate EOCRC incidence trends among Michigan adults aged 20–50 and identify ZIP-code level geographic disparities in incidence rates using publicly available surveillance data.

Methods: : A retrospective population-based cohort study was conducted using publicly available Michigan Cancer Registry data, SEER*Explorer, and NIH State Cancer Profiles from 2006–2020. Adults aged 20–50 with colorectal cancer (ICD-10 codes C18.x, C19, C20) were included. Individuals diagnosed before age 20 or after 50 were excluded. Analyses focused on ZIP code-level incidence variation. National incidence figures were used for benchmarking.

Results: : Statewide colorectal cancer incidence in Michigan declined from 52.9 to 41.4 per 100,000 between 2006–2020. However, adults aged 20–50 experienced a notable increase in EOCRC rates, especially among males. Rates rose from 6.2 to 8.9 per 100,000 between 2010 and 2022. Over 60% of EOCRC cases were diagnosed at Stage III or IV. Geographic analysis revealed significant ZIP-code level disparities, with higher incidence rates in urban areas compared to rural areas, suggesting localized differences in risk factors, screening access, or public health infrastructure.

Conclusions: : This study confirms a significant and rising burden of early-onset colorectal cancer (EOCRC) in Michigan’s younger population, highlighting substantial geographic disparities. These findings highlight the need to explore interventions that may enhance early detection and improve outcomes. Additional research is needed to explore underlying causes and to further detail care patterns and outcomes for these patients.

Sponsorship:: Priority Health and Pfizer, Inc.