Association of age, stage, and social vulnerability index with colon cancer diagnosis.

37 Background: Colon cancer diagnosed by screening often presents at stage I, offering much higher cure rates than symptom-detected cases at later stages. Stage at diagnosis can thus serve as a surrogate for screening access. Recent guidelines lowering the starting age for colonoscopy to 45 highlight the need to examine interactions between screening, healthcare access, and outcomes. The Social Vulnerability Index (SVI), ranging from 0-1, measures community vulnerability based on 16 U.S. Census variables, including socioeconomic status, minority status, housing, and transportation. This study investigates associations between age, stage at diagnosis, and SVI to understand disparities in colon cancer detection. Methods: Data used in this retrospective study came from Epic Cosmos, a dataset created in collaboration with a community of Epic health systems representing more than 300 million patient records from over 1700 hospitals and 40,000 clinics as of August 2025. The community represents patients from all 50 states . A project proposal was approved by Epic Cosmos. The base population chosen was patients aged 18 years or older with a new diagnosis term of “malignant neoplasm of colon” in Epic from April 1, 2022-March 31, 2025. The SlicerDicer tool was used to generate de-identified, aggregate-level data on age and stage at colon cancer diagnosis as well as US ZIP code-based SVI quartiles for the base population. Age categories were 40-44 years old and 45-50 years old based on the recommended age of 45 to start colon cancer screening. We excluded patients with missing data. Differences between groups were tested using chi-squared tests. Results: Complete data were available on 1367 patients for age/stage and 1349 patients for SVI/stage comparisons. Patients aged 40-44 and those in the highest SVI quartile (worst social vulnerability category) had significantly fewer stage I diagnoses compared to those aged 45-50 and those in better SVI quartiles, respectively (Table). Conclusions: The results suggest that the current recommendation of starting screening colonoscopies at age 45 may be helpful in diagnosing colon cancer at earlier stages (stage shift from II+ to I in the 45-50 years group). Patients of higher SVI are diagnosed at later stages compared to patients of lower SVI, potentially due to lack of access to healthcare resources. Public health efforts should prioritize early colon cancer screening for patients of all socioeconomic backgrounds. Age Group Stage I (% within Age Group) Stage II+ (% within Age Group) Total (%) p-value 40-44 years 26 (6.4) 379 (93.6) 405 (29.6) 45-50 years 127 (13.2) 835 (86.8) 962(70.4) Total 153 (11.2) 1214 (88.8) 1367 0.0003 SVI Group Stage I (% within SVI Group) Stage II+ (% within SVI Group) Total p-value Quartile 4 43 (9.7) 402 (90.3) 445 (33.0) Quartiles 1-3 128 (14.2) 776 (85.8) 904 (67.0) Total 171 (12.7) 1178 (87.3) 1349 0.0196 Quartiles 1-3 (SVI <25%, SVI 25-49%, and 50-74%) and Quartile 4 (SVI 75+%).