In a study reported in JAMA Oncology, Bitterman et al found that Black pediatric patients enrolled in Children’s Oncology Group (COG) trials were significantly less likely to receive proton radiotherapy than non-Hispanic White pediatric patients.
As stated by the investigators, “Proton radiotherapy is a high-cost, limited resource, for which the most robust evidence-based indications are in pediatric cancers owing to its ability to reduce long-term adverse effects compared with photon therapy … owing to potential barriers to proton radiotherapy access, we aimed to assess the association of race and socioeconomic factors with proton use in patients with solid malignant diseases enrolled on COG prospective trials.”
Study Details
Data for the analysis were provided by COG. Patients included in the analysis were United States residents who received external beam radiotherapy in COG solid tumor prospective trials that allowed physicians to choose proton or photon radiotherapy and were closed to accrual as of May 2018. Patients treated after 2010 were included in the analysis.
Key Findings
The total cohort included 1,240 patients treated from 2010 to 2018. Overall, 62% of the patients were non-Hispanic White, 11% were Hispanic, 13% were Black, 4% were another race, and race was unknown for 10%.
Among the 1,240 patients, 1,054 (85%) received photon radiotherapy and 186 (15%) received proton radiotherapy. Among those receiving proton therapy with known race, race was non-Hispanic White for 74%, Hispanic for 15%, Black for 7%, and other for 4%.
On univariate analysis, compared with non-Hispanic White patients, Black patients were significantly less likely to receive proton radiotherapy (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.22–0.75, P = .004). No significant differences were observed for Hispanic patients (OR = 1.09, 95% CI = 0.68–1.75, P =.72) or other patients (OR = 0.95, 95% CI = 0.41–2.17, P = .90) vs non-Hispanic White patents.
On multivariate analysis adjusting for enrolling institution location, distance to radiotherapy facility, and presence of metastatic disease, Black patients remained less likely to receive proton radiotherapy compared with non-Hispanic White patients (OR = 0.35, 95% CI = 0.17–0.72, P = .004). No significant differences were observed for Hispanic patients (OR =1.56, 95% CI = 0.89–2.73, P = .12) or other patients (OR = 0.65, 95% CI = 0.24–1.81, P = .41) vs non-Hispanic White patients.
On univariate analysis, proton radiotherapy use varied significantly according to geographic location of enrolling institution and was significantly less common among patients enrolled in non–central nervous system (CNS) vs CNS trials, patients with shorter vs longer distance between enrolling and radiotherapy institution, and patients with metastatic disease. No significant associations were observed for insurance type, neighborhood poverty level, or gender.
On multivariate analysis, all factors significant on univariate analysis remained significant except for CNS trial enrollment.
The investigators concluded, “Black pediatric patients were less likely to receive proton radiotherapy, despite being enrolled on national prospective trials in which treatment is highly standardized. Measures of socioeconomic status, including household-level (insurance) and area-level poverty, were not associated with proton radiotherapy…. The reported racial disparities are concerning, particularly as this cohort represents a selected population of patients treated in prospective national clinical trials. Our results suggest that a racial disparity in proton radiotherapy use may exist; additional confirmatory investigation is needed.”
Daphne A. Haas-Kogan, MD, of the Department of Radiation Oncology, Dana-Farber Cancer Institute, is the corresponding author for the JAMA Oncology article.
Disclosure: Study data were obtained from the COG, which is supported by a National Cancer Institute National Clinical Trials Network (NCTN) Operations Center grant, an NCTN Statistics & Data Center grant, and a National Institutes of Health Imaging and Radiation Oncology Core grant. For full disclosures of the study authors, visit jamanetwork.com.
