Widening inequality seen where cancer clinical trials are available

When someone has cancer, especially one that was discovered late or didn’t respond to the first options their doctors tried, they may qualify to join a clinical trial of a new potential treatment.

But now a study shows that such opportunities have remained scarce in certain counties considered to be socially vulnerable, which are often counties with the highest concentration of racial and ethnic minority groups and higher proportions of the population facing adversity on multiple measurements called social determinants of health.

That means that people living in socially vulnerable or disadvantaged counties have less access to the cutting-edge experimental options that could make a difference in their care, and help shape the future of cancer care for others, say the researchers from the University of Michigan’s Rogel Cancer Center who published the findings in JAMA Network Open.  

The study comes even as cancer researchers and research funders have made special efforts to enroll more diverse groups of patients into cancer clinical trials, especially at major cancer centers like Rogel.

The researchers used a standard measure developed by the Centers for Disease Control and Prevention called the Social Vulnerability Index, which combines data about a county’s population including poverty and unemployment levels, education levels, disability, age, housing type and living arrangements, access to transportation and racial and ethnic backgrounds.

On the SVI scale, a higher score means a county has a more socially vulnerable population.

Lead researcher Rishi Sekar, M.D., M.S., and colleagues combined county-level SVI with data about the availability of Phase II and III clinical trials in each county, as well as cancer epidemiology data.

They focused on treatment trials for prostate, breast, lung, colorectal, bladder, uterine, kidney and melanoma skin cancer listed on clinicaltrials.gov, the national registry of all clinical trials.

“For a long time our health care system has focused on cancer centers scattered throughout the country, where we expect patients to come for complex cancer care including access to clinical trials,” said Sekar.

“If we want to make access to promising new treatments more equitable, we need to reimagine this into a hub and spoke model where trial participation can be improved and augmented with utilization of telehealth and partnerships with community hospitals and satellite clinics. We need to bring clinical trial opportunities into the communities we hope to serve and engage with.”

This will require efforts to ease the regulatory burdens that might keep clinics and hospitals in high-vulnerability counties, which are often under-resourced, from becoming trial sites, adds Sekar, who’s a urologic oncology fellow in the Department of Urology.

He is also a clinician scholar in the National Clinician Scholars Program at the U-M Institute for Healthcare Policy and Innovation, and a postdoctoral fellow in Cancer Care Delivery Research at the Rogel Cancer Center.

Key findings

• Counties with greater social vulnerability were less likely to have a cancer clinical trial available, ranging from about 50% in the most vulnerable counties to 70% in the least vulnerable counties.
   
• Similarly, the most socially vulnerable counties had far fewer clinical trials on average at around 200 compared to the least socially vulnerable counties at nearly 600 (reported per 100,000 people). 
   
• Although the number of clinical trials available across the country has grown from 2007 to 2022, they are predominantly concentrated in the least socially vulnerable counties, and this disparity has dramatically worsened over time.

“Federal agencies and academic medicine have been talking about this problem for decades, and though the number of trials and trial sites has increased, they are still predominantly concentrated where they have always been. We continue to exclude the very communities we want to include,” he said.

“We hope this study will help cancer leaders identify communities where they could expand trial opportunities and improve access.”

He notes that the new data supports efforts by the National Cancer Institute’s Community Oncology Research Program which has been working to expand trial opportunities into communities with high proportions of people from racial and ethnic minority groups that have been under-represented in trials in the past.

Sekar and his colleagues are continuing to study new ways of looking at equity in access to cancer clinical trials, down to the patient level.

In the meantime, the Rogel Cancer Center is working to understand each patient’s needs by asking about social determinants of health such as access to transportation and family support, adequate food and ability to afford medications.

Rogel and other cancer centers have begun hiring care coordinators who can help patients overcome barriers they may face, to help support them as they receive treatment and take part in clinical trials.

In addition to Sekar, the authors are Lindsay Herrel, M.D., M.S. and Kristian Stensland, M.D., M.P.H., M.S.

The study was funded by the Bladder Cancer Advocacy Network, and Sekar’s postdoctoral position is funded by the National Cancer Institute under a T32 training grant (CA236621).

Paper cited: “Social Determinants of Health and the Availability of Cancer Clinical Trials in the United States,” JAMA Netw Open. DOI: 10.1001/jamanetworkopen.2024.10162