Willingness to Discuss Clinical Trials among Black vs White Men with Prostate Cancer

Importance: Black individuals are underrepresented in cancer clinical trials. Objective: To examine whether Black and White men with prostate cancer differ in their willingness to discuss clinical trials with their physicians and, if so, whether patient-level barriers statistically mediate racial differences. Design, Setting, and Participants: This cross-sectional survey study used baseline data from Partnering Around Cancer Clinical Trials, a randomized clinical trial to increase Black individuals' enrollment in prostate cancer clinical trials. Data were collected from 2016 through 2019 at 2 National Cancer Institute-designated comprehensive cancer centers; participants were Black and White men with intermediate-risk to high-risk prostate cancer. In mediation analysis, path models regressed willingness onto race and each potential mediator, simultaneously including direct paths from race to each mediator. Significant indirect effect sizes served as evidence for mediation. Exposures: Race was the primary exposure. Potential mediators included age, education, household income, perceived economic burden, pain/physical limitation, health literacy, general trust in physicians, and group-based medical suspicion. Main Outcomes and Measures: The primary outcome was the answer to a single question: "If you were offered a cancer clinical trial, would you be willing to hear more information about it?" Results: A total of 205 participants were included (92 Black men and 113 White men), with a mean (range) age of 65.7 (45-89) years; 32% had a high school education or lower, and 27.5% had a household income of less than $40000. Most (88.3%) reported being definitely or probably willing to discuss trials, but White participants were more likely to endorse this highest category of willingness than Black participants (82% vs 64%; χ²₂= 8.81; P =.01). Compared with White participants, Black participants were younger (F_1,182= 8.67; P <.001), less educated (F_1,182= 22.79; P <.001), with lower income (F_1,182= 79.59; P <.001), greater perceived economic burden (F_1,182= 42.46; P <.001), lower health literacy (F_1,184= 9.84; P =.002), and greater group-based medical suspicion (F_1,184= 21.48; P <.001). Only group-based medical suspicion significantly mediated the association between race and willingness to discuss trials (indirect effect, -0.22; P =.002). Conclusions and Relevance: In this study of men with prostate cancer, most participants were willing to discuss trials, but Black men were significantly less willing than White men. Black men were more likely to believe that members of their racial group should be suspicious of the health care system, and this belief was associated with lower willingness to discuss trials. Addressing medical mistrust may improve equity in clinical research..