Racial diversity in clinical trials: Barriers and opportunities

The Stanford Cancer Institute (SCI) prioritizes the inclusion of diverse patients from underrepresented backgrounds in cancer clinical research. It’s particularly important that patients participating in cancer clinical trials represent the people who live in the 10-county catchment area of the cancer center. Data from the Stanford Cancer Registry and Clinical Trial Management System show that Latinos and Asian-Americans participate in SCI clinical trials at rates that closely match their representation in the catchment area (18.3% and 19%, respectively). The SCI catchment area has a 6.5% African-American population, yet only 3.5% of the SCI patients on clinical trials are Black or African-American. The SCI has made it a goal to expand access and increase the accrual of the African-American population to match their representation in SCI's catchment area. 

Dinah Trevil, MPA, Senior Program Director at the SCI Office of Cancer Health Equity, explains the obstacles cancer centers face in recruiting a more diverse patient population and strategies we can implement to meet this challenge.

Lack of information about clinical trials

Communities that are underrepresented generally don’t have information about the benefits of clinical trials, how to enroll, and how to participate. This is due to a lack of diverse resources and materials that these communities can relate to in terms of information pertinent to clinical trials. 

Clinicians may also have an unconscious bias originating from previous experience with specific racial and ethnic groups that these populations will have issues with medical adherence. As a result, they may choose to not introduce and talk to these patient populations about clinical trials. 

Lack of access 

Many factors impact access, particularly how far away underrepresented communities are from the SCI and Stanford Health Care. Other issues include insurance, English language proficiency, and financial hardship that may result from enrollment, such as the need to take time off work to participate in a clinical trial.

Exclusion criteria and mistrust of medical research

Finally, clinical trials often exclude patients who have comorbidities due to concerns that the comorbidity may adversely impact the evaluation of the intervention’s efficacy. Unfortunately, in underrepresented populations, this can prevent patients who are otherwise eligible from enrolling.

People in underrepresented communities may also not trust medical research to be safe and choose not to enroll based on this fear. 

Meet people where they are–geographically and culturally–to improve diversity

The SCI plans to: 

  • Expand trials in the Stanford Health Care network, in the South Bay and the East Bay

  • Increase supportive services

  • Implement new services, such as education and navigation services, to make it easier for patients to consider and participate in clinical trials

  • Advocate and work towards a simplification of restrictions currently limiting  clinical trial participation, such as loosening exclusion criteria, using clear language for improved understanding, providing  translated consent forms for trials

Trevil also speaks to the importance of diversifying the clinician and clerical workforce to be more representative of the communities that the SCI is trying to reach. An example program she provides is partnering with Historically Black Colleges and Universities (HBCUs) to implement initiatives and programs where students partner with Stanford clinicians and researchers.  

Finally, organization-wide Justice, Equity, Diversity, and Inclusion (JEDI) practices and implicit bias in research training will help researchers and staff successfully engage underrepresented communities and adapt the information to be culturally relevant and address the community’s concerns and hesitancies toward enrolling. 

Build trust and community engagement

Trevil underscores the importance of first establishing trust and a relationship with key community stakeholders before engaging in and introducing the topic of clinical trials. When the topic can be introduced, community input and feedback will be required to improve community engagement. 

“We have to be very strategic and intentional in our efforts, and we have to be adaptable and flexible as we establish a relationship with the community and encourage their participation in future clinical trials.”


January 2023