Care delivery among patients with early-onset versus average-onset cholangiocarcinoma: A nationwide retrospective analysis.

487 Background: While most patients with cholangiocarcinoma (CCA) belong to older age groups (≥65 years), the incidence of early-onset cholangiocarcinoma (EOCCA, <50 years) is rising. Data from other early-onset cancers, such as colorectal cancer, show significant diagnostic delays, yet studies examining diagnostic timelines in EOCCA are lacking. We investigated diagnostic delays between EOCCA and average-onset CCA (AOCCA, ≥50 years) using a large claims-based database. Methods: Using Komodo Healthcare Map claims data (2017-2024), patients with CCA were identified by ICD-10 codes and classified as EOCCA (<50 years) or AOCCA (≥50 years). ICD-10 codes for common CCA symptoms were used to estimate time from earliest documented symptom onset to diagnosis and from diagnosis to first intervention. Interventions were classified as surgery, systemic, or palliative. Chi-square tests compared demographics between groups. Univariate and multivariate log-gamma regression models were used to identify factors associated with diagnostic and intervention delays; logistic regression was used to evaluate differences in type of intervention and odds of diagnostic delay beyond 30 days. Statistical significance was set at 5% using R v4.2.1. Results: Of 116,106 patients, 5,146 (4.4%) were EOCCA. Compared with AOCCA, EOCCA patients were more often female (52.2% vs 48.5%), African American (16.3% vs 11.7%), Hispanic (20.9% vs 13.2%), and had Medicaid (30.9% vs 6.4%) or Commercial insurance (56.6% vs 15.7%). Among 43,137 patients presenting with symptoms before diagnosis, EOCCA was associated with higher odds of diagnostic delays overall (exp(Beta) 1.13, 95% CI 1.07–1.20, p<0.001) and beyond 30 days (OR 1.24, 95% CI 1.12–1.36, p<0.001), with a median delay of 51 days. Female EOCCA patients were particularly affected (p<0.01). Of 52,444 patients treated within 6 months, time to first intervention did not differ by age group (exp(Beta) 0.98, 95% CI 0.95–1.02, p=0.42). On multivariable analysis, EOCCA patients were more likely to receive systemic versus palliative therapy than AOCCA (OR 1.12, 95% CI 1.01–1.25, p=0.03). Among EOCCA, disparities in time to first intervention by sex, race, rurality, or insurance were not significantly different from AOCCA. Conclusions: EOCCA is associated with statistically significantly greater diagnostic delays than AOCCA, especially among women. These findings underscore the need for age-tailored care pathways to reduce delays and optimize outcomes. Prospective studies should define interventions that expedite diagnosis and address barriers unique to EOCCA.