EP162 - Does Age or Address Matter? Survival Outcomes in Young-Onset vs. Average-Onset Colon Cancer

Purpose/Background: The prognostic significance of young-onset colorectal cancer (YOCRC), defined as diagnosis before the age of 50, remains controversial. Patients with YOCRC account for approximately 15% of all new colorectal cancer diagnoses in the U.S. Some studies suggest more aggressive tumor biology and worse outcomes, while others report improved survival compared to average-onset colorectal cancer (AOCRC). Clarifying these differences is essential to guide treatment and survivorship strategies. Moreover, social determinants of health (SDoH) may further influence outcomes and confound age-related comparisons. This study aimed to evaluate the overall survival (OS) of patients with YOCRC compared to AOCRC, incorporating neighborhood- level SDoH using the Area Deprivation Index (ADI).

Methods/Interventions: We performed a retrospective cohort study cohort study of patients diagnosed with colon cancer between 2016 and 2020 at the University of Pittsburgh Medical Center (IRB #24020109). Patients were categorized as young onset ( < 50yrs.) or average onset (>50 yrs.). Those exactly age 50 or with inflammatory bowel disease associated cancer were excluded. The ADI was used as a proxy for SDoH. Kaplan Meier and Cox proportional hazards analysis were used to compare the OS between the two groups and to assess the impact of ADI, with subgroup analyses by stage at diagnosis.

Results/Outcomes: Among 2,153 patients, those with YOCRC demonstrated superior OS compared to AOCRC (p=0.02), with a 44% lower hazard of mortality (HR=0.56, p=0.02) Stage-specific analyses showed significantly higher OS for YOCRC patients with stage II (p=0.05) and stage III disease (p=0.01), with a 61% lower mortality hazard in stage III YOCRC (HR=0.39, p=0.04). No significant differences were observed in stage I or IV disease. ADI quartile did not modify the age-related survival difference; however, independent of age, patients residing in the most socially deprived areas had worse OS (HR=1.42, p=0.02).

Conclusion/Discussion: Despite conflicting literature on the survival outcomes of YOCRC compared to AOCRC, our data show that younger patients-particularly those with stage III disease-have improved survival compared to older counterparts. Nonetheless, socioeconomic deprivation remains a predictor of mortality, independent of age, underscoring the need to consider neighborhood-level disparities alongside tumor biology in understanding colon cancer outcomes..

Overall Survival Young Onset compared to Average Onset Stage III Colon Cancer
Kaplan - Meir curve demonstrates higher overall survival among young onset colon cancer patients with stage III disease compared to patients with average onset colon cancer with stage III disease