Participation in Cancer Clinical Trials: Why Are Patients Not Participating?

Background. Participation in cancer clinical trials is low, particularly in racial and ethnic minorities in some cases, which has negative consequences for the generalizability for study findings. The objective of this study was to determine what factors are associated with patients' participation or willingness to participate and whether these factors vary by race/ethnicity. Design or Methods. White, Hispanic, and black participants were obtained through the Florida cancer registry and who were diagnosed with breast, lung, colorectal, or prostate cancer (N = 1100). Participants were surveyed via telephone to obtain demographic information, past participation, and willingness to participate in clinical trials, as well as barriers and facilitators to participation. Logistic and Poisson regressions were performed. Results. Respondents were on average 67.4 years old, 42.7% were male, and 50.1% were married. In this population, 7.7% of respondents had participated in a clinical trial, and 36.5% stated that they would be willing to participate. In multivariate models, blacks and Hispanics were equally likely as whites to be willing to participate in cancer trials, but Hispanics were less likely to have participated, and this was especially more likely in non-English-speaking Hispanics compared with English-speaking Hispanics. Notable barriers across race/ethnicity were mistrust and lack of knowledge of clinical trials. Limitations. Cross-sectional design limits cause-and-effect conclusions. Conclusions. There are racial differences in participation rates but not in willingness to participate. We hypothesize that willingness to participate is not very high because people are uninformed about participating, particularly in non-English-speaking Hispanics. Barriers and facilitators to participation vary by race. Improved understanding of cultural differences that can be addressed by physicians may restore faith, comprehension, and acceptability of clinical trials by all patients.