Sociodemographic disparities among patients referred externally for clinical trials in a large community oncology setting.

Abstract

e13756 Background: The vast majority of patients with cancer are seen in community oncology settings, yet enrollment onto clinical trials –which are primarily conducted at academic centers– remains low. Barriers to referral for clinical trials outside of a patient’s home institution include lack of trial awareness among patients and oncologists, geographic and transportation challenges, insurance concerns, and onerous care coordination between healthcare systems. These barriers may be heightened for patients from historically racial/ethnic minoritized groups, socioeconomically disadvantaged backgrounds, or those with language barriers. This study aimed to evaluate the sociodemographic characteristics of adult patients who were referred to external institutions for interventional cancer clinical trials. Methods: We retrospectively evaluated patients who were referred to external institutions for interventional cancer clinical trials between 1/1/2023-12/31/2023, identified using Kaiser Permanente Northern California billing data. Patients with Medicare plans were excluded as external clinical trials are billed directly to Medicare. We compared patients’ sociodemographic and clinical characteristics to an incident non-Medicare cancer population diagnosed between 6/1/2022-5/31/2023 across KPNC. Due to a six-month lag in the KPNC cancer registry data, we adjusted the comparison cohort’s study period. Statistical analyses included Pearson chi-squared tests (categorical), binomial tests (binary) and one-sample t-tests (continuous). Results: 110 patients were externally referred for clinical trials over the study period and were compared to the incident cancer cohort (n = 3395). Patients referred externally were more likely to come from high socioeconomic neighborhoods (40% vs 24%), have distant SEER staging (70% vs 13%), and have rarer tumor types, such as sarcoma (9% vs 1%) or brain malignancy (7% vs 1%), compared to the incident cancer cohort. A higher proportion of male patients were referred (56% vs 38%) (all p-value < 0.05). Conversely, there were no population differences based on race/ethnicity, age, or primary language spoken. Conclusions: Patients with rare tumor types and metastatic disease were more highly represented among those referred for external clinical trials compared to the incident cancer population. Despite a similar racial/ethnic distribution between the two populations, patients from low SES neighborhood were less likely to be referred. These findings suggest that structural barriers may persist in accessing trials, even within an integrated health system. As trials become more personalized with the advent of precision oncology and increasing biomarker-driven studies, including in the early-stage setting, health systems must work to surmount these barriers and facilitate equitable access to clinical trials.