Disparities in patient enrollment of spinal oncology clinical trials

Subpopulation underrepresentation in clinical trials contributes to biases in clinical data and systemic healthcare inequities. We aim to evaluate reporting and representation, as well as the effect of geography and socioeconomic trends, in spinal oncology trials.

Data were collected from completed spinal oncology trials registered on ClinicalTrials.gov from 2000 to 2023. A total of 42 trials with 5679 participants were included. The demographics of participants were compared with national spinal tumor incidence data and demographic data from patients undergoing spinal oncology surgery at a quaternary care center.

Only 50% of clinical trials reported race and 28.6% reported the ethnicity of participants, with privately funded trials less likely to report ethnicity (25% vs. 66.7%, P = .02574). When compared with their respective national incidences, Black (4.6% vs. 11.3%, P < .00001), American Indian or Alaska Native (0.2% vs. 0.6%, P = .00084), and Hispanic (4.7% vs 11.4%, P < .00001) patients were significantly underrepresented in trials. Black (4.6% vs. 18.9%, P < .00001) and female (44.5% vs. 48.9%, P = .00438) patients were also underrepresented when compared with the population of patients undergoing spinal oncology surgery. Trials post-2020 had increases in representation of several minority groups compared to pre-2020 trials. Trial sites were mostly located in metropolitan areas, with gaps in the Mountain region and parts of the Southern U.S.

There has been progress in diversifying spinal oncology trials, but there are still large racial, ethnic, and geographic disparities in the composition of clinical trial patients. Major reporting lapses hinder understanding the gaps in equitable enrollment.