More Patients Participate in Cancer Treatment Trials Than Previously Estimated

— Study calculates rate at 7.1%, higher than historical estimate of less than 5%

 A photo of a chair next to chemotherapy equipment.

Participation in cancer treatment clinical trials was higher than historical estimates, according to a national sample of data from the Commission on Cancer.

From 2013 to 2017, the overall estimated participation rate in cancer treatment trials was 7.1%, which was higher than historical estimates of less than 5%, reported Joseph M. Unger, PhD, of the Fred Hutchinson Cancer Center in Seattle, and colleagues.

Cancer treatment trial participation estimates have been based on studies of enrollment in National Cancer institute (NCI)-sponsored cooperative group trials, with estimates ranging from 1.5% to 4%, the authors noted in the .

"But patients also routinely participate in trials sponsored by pharmaceutical companies that enroll at least as many patients as NCI-sponsored trials," they wrote. "Our estimate that 7.1% of patients participate in treatment trials is consistent with this premise and reflects recent studies suggesting that overall treatment trial participation is between 6% and 8%."

These estimates are similar to those reported in other industrialized nations, such as the U.K. and France, Unger and team added. Moreover, at least one in five patients (21.9%) contribute to any kind of clinical research study.

"Participation in cancer clinical research studies still has room for improvement," they noted. "Nonetheless, these results suggest that contributions to clinical research for adults with cancer is more common than is typically realized."

In an , Catherine C. Fahey, MD, PhD, of the Vanderbilt University Medical Center in Nashville, Tennessee, and W. Kimryn Rathmell, MD, PhD, of the National Cancer Institute, pointed out that enrollment in clinical trials has a critical impact on the goals laid out by the and the .

Accordingly, the study by Unger and colleagues is "a new key update to our understanding of clinical trial enrollment patterns and should be commended for assembling and analyzing real-world data from available data sets that are reasonably representative of the population activities in clinical trial enrollment," they wrote.

The Commission on Cancer requires member institutions to submit accreditation information every 3 years, including information on clinical trial enrollment. In this study, the authors used data from 1,200 programs, representing more than 70% of all cancer cases diagnosed in the U.S. each year.

The most common program types included community cancer programs (75.7%), followed by academic (non-NCI-designated) comprehensive cancer programs (15%), integrated network cancer programs (5.8%), and NCI-designated comprehensive cancer center programs (3.6%).

In addition to cancer treatment trial enrollments, Unger and colleagues estimated participation in a variety of other study types, including biorepository (12.9%), registry (7.3%), genetic (3.6%), quality of life (2.8%), diagnostic (2.5%), and economic (2.4%) studies.

Overall participation in any category of study was estimated to be at least 21.9%. If biorepository studies were excluded, the estimate was 17.6%, and if both biorepository studies and registry studies were excluded, the estimate was 14.3%.

Treatment trial enrollment was 21.6% for NCI-designated comprehensive cancer center programs, 5.4% at academic (non-NCI-designated) comprehensive cancer programs, 5.7% at integrated network cancer programs, and 4.1% at community programs.

These participation estimates "highlight the fact that the majority of patients continue to receive care outside of NCI-designated cancer centers," Fahey and Rathmell noted. "As such, it is crucial to have data representative of all centers, such as the data presented in this paper. Recognizing the range of variation in clinical trials enrollment is as important as knowing the overall median."

Unger and colleagues pointed out that NCI-designated cancer center programs receive dedicated federal funding to conduct clinical trials, "the kind of support not typically available for other programs, especially community-based sites where most patients in the United States receive their care."

Therefore, they added, any efforts to increase trial enrollment will depend on providing the infrastructure and staff support needed to conduct trials at non-NCI-designated sites.

"This reality reflects the need to optimize the workforce as a recognized priority of the National Cancer Plan and a key element of the Cancer Moonshot initiatives," Fahey and Rathmell observed.

Unger and team acknowledged several limitations to their study, including the fact that Commission on Cancer institutions are larger, more likely to be located in urban centers, and have more cancer-related services than non-approved institutions, which could limit the generalizability of the study's participation estimates.

They also said that it wasn't possible to examine trial participation according to factors such as sex, race, ethnicity, or geography.

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    Mike Bassett is a staff writer focusing on oncology and hematology. He is based in Massachusetts.


The study was supported by the Public Health Sciences Division of the Fred Hutchinson Cancer Center.

The study authors and editorialists reported no conflicts of interest.

Primary Source

Journal of Clinical Oncology

Unger JM, et al "National estimates of the participation of patients with cancer in clinical research studies based on Commission on Cancer Accreditation data" J Clin Oncol 2024; DOI: 10.1200/JCO.23.01030.

Secondary Source

Journal of Clinical Oncology

Fahey CC, Rathmell WK "Clinical trials -- real-world data to build a future for our patients" J Clin Oncol 2024; DOI: 10.1200/JCO.24.0037.