Age, racial, and ethnic disparities in reported clinical studies involving brachytherapy

The purpose of this study was to evaluate for age, racial, and ethnic disparities among clinical studies where patients can potentially receive brachytherapy treatment.

Trials involving brachytherapy for breast, cervical, prostate, and uterine cancers were identified using ClinicalTrials.gov. The age, racial, and ethnic breakdown of the identified trials were compared to US population-estimates derived from the Surveillance, Epidemiology, and End Results (SEER) Program. Primary outcomes were gaps between gaps between mean age and race and ethnic proportions in trials and the US population. Secondary outcomes included proportions of racial and ethnic data reporting. Descriptive statistics, t-tests, χ2 tests, and univariate analysis were used to analyze the data.

A total of 77 trials with reported data were identified, representing 13,580 patients. The overall difference in mean age in the identified trials compared to US population estimates was -2.29 years (p < 0.001), with the largest difference occurring in prostate cancer at -2.72 years (p < 0.001). With the exception of ethnicity in cervical cancer (p = 0.18), all racial and ethnic distributions were statistically significantly different. Overall, the largest disparity was among Asian (-2.65%) and Hispanic patients (-1.05%). Of the 77 trials, 76 (98.7%) reported age, 36 (46.8%) reported race, and 24 (31.2%) reported ethnicity.

Diversity data is underreported among clinical studies where brachytherapy is a potential treatment component. However, among reported trials, disparities are present albeit relatively small compared to previous studies reporting on disparities in clinical trials. Future efforts should emphasize increased reporting of racial and ethnicity data as well as ensuring inclusion of older patients and minorities.