Barriers keeping breast cancer patients out of clinical trials

Clinical trials are critical for patients with breast cancer to access the newest, most advanced treatments; however, participation rates can be low, especially among Black and Hispanic communities.

In order to improve the enrollment of more diverse breast cancer patient populations in clinical trials, researchers from the University of Chicago Medicine Comprehensive Cancer Center evaluated barriers that prevent patients from racial and ethnic minority groups from participating in clinical trials.

The findings from their study, which was recently published in JAMA Network Open, provide valuable insights for expanding access to clinical trials to ensure inclusion of breast cancer patients from underrepresented racial and ethnic groups.

“Clinical trials allow access to novel therapies and therapeutic strategies for our patients that we otherwise could not provide,” said Nan Chen, MD, co-first author of the study and Assistant Professor of Medicine at UChicago. “Furthermore, more equitable clinical trial participation would allow trials to more closely mirror the real-world experience of breast cancer both in the United States and globally.”

Chen and team evaluated survey responses from 1,150 patients enrolled in the Chicago Multiethnic Epidemiologic Breast Cancer Cohort (ChiMEC) — a hospital-based study focused on understanding factors that affect cancer risk, with a focus on health disparities and diverse participants from Chicago. The self-reported demographic mix of respondents was 4.4% Asian, 19.5% Black, 3.1% Hispanic and 73% white. The team was interested in responses about discussing a breast cancer clinical trial with a healthcare practitioner, participating in a clinical trial when offered, and barriers to trial enrollment.

A total of 447 respondents (38.9%) reported discussing a breast cancer clinical trial with a healthcare practitioner, with no differences in trial discussion between white patients and other racial groups.

Among 443 patients offered a trial, 285 (64.3%) participated, with no major differences between racial groups after adjusting for sociodemographic and clinical factors.

“This is consistent with other datasets that have also noted similar rates of clinical trial participation across racial groups. However, this does counter against some physician biases that some racial groups may be less amenable to clinical trial participation,” Chen explained.

When compared with patients who did not discuss a trial with a provider, those who did were younger, were enrolled in ChiMEC within the last five years, had a higher stage of cancer, were more likely to be diagnosed with triple-negative breast cancer (TNBC), and had a high-grade tumor.

“This may reflect the University of Chicago’s focus on trials for advanced breast cancer or TNBC occurring more frequently in Black patients that we see at our cancer center,” said Jincong (Jason) Freeman, co-first author of the study and a doctoral student in Public Health Sciences at UChicago.

Among 158 patients who did not enroll in the trial offered, 37 (23.4%) reported ineligibility, 17 (10.8%) were worried about the possibility of getting a placebo, 16 (10.1%) were worried about extra time required, and 14 (8.9%) were worried about possible adverse effects.

“Ineligibility, concern for getting a placebo, and time toxicity are concerns we can address with thoughtful clinical trial design and improved clinical trial education with our patients,” Chen said. For example, less strict eligibility criteria could allow for more patients to be included.

“Although eligibility is important to ensure that patients safely participate in clinical trials, we must also be thoughtful to not be too limiting to discourage patients from participating,” she said.

She added that certain racial groups more commonly have other medical conditions that may make them ineligible, but excluding these patients from trials can inadvertently worsen disparities in clinical trial participation.

Additionally, because time is such an important concern, clinical trials could be structured in a way that reduces additional visits and streamlines study schedules. In addition, efforts can be made to offer clinical trial procedures and activities closer to home and more conveniently for patients to decrease the additional time needed to participate. “And I think telehealth can be a great tool used for study trial follow-ups that do not require in-person visits. Some of the activities can be done virtually, such as reporting of treatment side effects, reviewing lab results, and follow-up surveys,” Freeman added.

For example, UChicago Medicine is a founding member of the Chicago Breast Cancer Research Consortium (CBCRC), which will open breast cancer clinical trials across the Chicagoland area. This consortium will also have funds that can help with patient parking, meals and childcare, which can significantly impact the financial toxicity of extra trips to the clinic.

Improved patient education about how clinical trials are conducted could address other concerns, such as receiving placebos. For example, therapeutic trials typically test whether a new treatment is better than the current standard of care. In other words, patients on clinical trials will always receive at least the standard of care treatment for their cancer.

“The majority of oncology studies do not use a true placebo in the sense that patients aren’t receiving any treatment for their cancer,” Chen explained. “This would only be the case if the standard therapy would be no treatment.”

In summary, the study demonstrated that when offered, patients across racial and ethnic groups were equally likely to participate in clinical trials. In addition to ineligibility, extra costs and burdens on patients’ time were significant barriers to enrollment.

These data provide valuable insights that can serve as a roadmap for how to expand access to trials for all patients, regardless of racial, ethnic and socioeconomic background.

However, more studies are needed to untangle the systemic, institutional and clinician-based barriers and biases to clinical trial participation.

“In the future, we hope to collect data about clinical trial participation prospectively, for physicians and patients alike,” Chen said. “We aim to better understand how physician biases are influencing patient trial enrollment and more accurately evaluate patient barriers to more equitable clinical trial participation.”

Freeman added that it would be worthwhile to learn more about participation rates and barriers among newly diagnosed patients compared to patients whose cancer had come back.

“Most patients in this study were diagnosed with early-stage, and some of them may have had a recurrence along their journey. This can be addressed in future research,” he said.

The study, “Clinical Trial Discussion and Participation in a Breast Cancer Cohort by Race and Ethnicity,” was published in JAMA Network Open on June 12, 2025. It was supported in part by the Breast Cancer Research Foundation, the National Cancer Institute, the Susan G. Komen Breast Cancer Foundation, and the National Institute on Aging.

Additional authors included Fangyuan Zhao, PhD, MA, Leah Goldberg, MD, Sudha R. Yarlagadda, MD, Elizabeth Terman, MD, Dezheng Huo, MD, PhD, and Rita Nanda, MD, from the University of Chicago.