Barriers to Patient Enrollment in Therapeutic Clinical Trials for Cancer: A Landscape Report

October 2018 Vol 9, NO 10


Clinical Trials
Ted A. James, MD, MHCM, FACS
Beth Israel Deaconess Medical Center
Harvard Medical School. Boston, MA

Oncology clinical trials have greatly advanced treatment options for patients with cancer, resulting in remarkable improvements in survival and well-being. The literature, however, continues to report low rates of accrual to cancer clinical trials, with estimates that less than 5% of adult patients with cancer actively participate in clinical research.1-3 Despite considerable research into the challenges of trial participation, enrollment rates have not improved substantially over time. If this trend continues, there will be a crisis with respect to new discovery in oncology. Furthermore, underrepresentation of particular demographic and socioeconomic groups in many clinical trials has been recognized as an ongoing problem.4,5 Low clinical trial accrual and lack of diversity not only impede patient access to new treatments, they also delay trial completion and limit generalizability of the findings to the overall population. Consequently, approximately 20% of cancer-related clinical trials fail due to insufficient patient enrollment.6

The American Cancer Society Cancer Action Network (ACS CAN) has produced a landscape report on barriers to patient enrollment in therapeutic clinical trials for cancer and developed consensus recommendations for overcoming these challenges. The report states that although many patients express a willingness to participate in cancer-related clinical trials, barriers to participation result in only a small proportion actually enrolling. The authors comment that participation in clinical trials often requires a multistep process that patients must navigate to the end, and enrollment is only successful if previous barriers have not been encountered along the way. The recommendations outlined in the report provide a comprehensive array of proposals and strategies to help rectify the problem. These recommendations include suggestions for resource development, funding allocation, process improvement, and patient engagement. Notably, the report calls for a much-needed modernization of clinical trial eligibility to reduce unnecessary exclusion of patients (eg, elderly, particular demographic groups, patients with comorbidities). It is important to ensure that neither the eligibility criteria nor the recruitment process itself excludes certain demographic or socioeconomic groups unless specific rationale for exclusion exists. The report also highlights the need to provide clinical trial navigation services for patients from medically underserved groups to connect with publicly available support resources and culturally sensitive education materials. These are areas where oncology nurse navigators may be able to have an impact on increasing access to and participation in clinical trials. Less than 10% of patients enrolled in clinical trials represent patients from diverse backgrounds. An innovative patient navigation model for clinical trials was implemented at one institution and successfully recruited and retained greater ethnic diversity in a therapeutic oncology trial compared with nonpatient navigation trial participation.7 This approach holds promise for the role that oncology nurse navigators may play in improving inclusiveness in cancer clinical trial participation. Intake navigators working in conjunction with clinical trial coordinators can ensure that all newly diagnosed patients eligible for clinical trials are identified and offered opportunities to learn more about enrollment. Moreover, oncology nurse navigators may be helpful in overcoming challenges to recruiting patients for clinical trials in survivorship, which has proved to be a particularly difficult but much needed area of research. Given the growing number of adult cancer survivors, there is an increasing need for data that can inform management of late effects of cancer treatment and help determine best practices for survivorship care. Pilot studies have demonstrated that discussing the availability of clinical research with patients during survivorship care visits enhances accrual to clinical trials in the survivorship phase of care.8

Another promising opportunity to drive patient engagement in clinical research is by partnering with patients in the design and implementation of cancer trials. Obtaining direct input from patients on protocol design, study conduct, and analysis would help to ensure that clinical trials meet the needs of patients, adequately address patients’ concerns related to research, and focus on research priorities of greatest importance to patients with cancer. This type of research collaboration would facilitate buy-in and trust, which have the potential to significantly increase trial enrollment. Patients would help to raise clinical trial awareness by communicating current research initiatives widely among patient communities. Online communities and patient advocacy groups become vital centers for research development and patient recruitment. Partnering directly with patients through social media also enables rapid identification of patients willing to support and participate in clinical research. Providing resources, tools, and information to enable patients to partner with clinical researchers, or to lead clinical research themselves, opens up a vast and previously untapped source of highly engaged and motivated investigators. Policy, funding, and institutional support are required to promote these types of endeavors in cancer research. This patient-driven model of cancer research may help expedite clinical investigation in oncology and accelerate new discoveries and treatments.

Ultimately, the ability to integrate clinical trials into the daily operations of patient care, as well as to remove known obstacles to participation, will serve to improve enrollment and strengthen the impact of clinical research. This is of utmost importance if we are to continue to make progress in the care of patients with cancer through clinical innovation. The ACS CAN landscape report takes a substantial step forward by outlining how to expand the reach of available trials to patients and improve the system to facilitate accrual. It is now up to the cancer community to ensure that the momentum of these efforts leads to enhancing the quality of clinical research for the betterment of our patients.


  1. Unger JM, Cook E, Tai E, Bleyer A. The role of clinical trial participation in cancer research: barriers, evidence, and strategies. Am Soc Clin Oncol Educ Book. 2016;35:185-198.
  2. Murthy VH, Krumholz HM, Gross CP. Participation in cancer clinical trials: race-, sex-, and age-based disparities. JAMA. 2004;291:2720-2726.
  3. Tejeda HA, Green SB, Trimble EL, et al. Representation of African-Americans, Hispanics, and whites in National Cancer Institute cancer treatment trials. J Natl Cancer Inst. 1996;88:812-816.
  4. Weinberg AD. The EDICT Project: Policy Recommendations to Eliminate Disparities in Clinical Trials. ResearchGate. 10.13140/RG.2.2.17044. 40321. 2008.
  5. Mills EJ, Seely D, Rachlis B, et al. Barriers to participation in clinical trials of cancer: a meta-analysis and systematic review of patient-reported factors. Lancet Oncol. 2006;7:141-148.
  6. American Cancer Society Cancer Action Network. Barriers to Patient Enrollment in Therapeutic Clinical Trials for Cancer: A Landscape Report. 2018.
  7. Fouad MN, Acemgil A, Bae S, et al. Patient navigation as a model to increase participation of African Americans in cancer clinical trials. J Oncol Pract. 2016;12:556-563.
  8. Rosenberg SM, Ligibel JA, Meyerhardt JA, et al. Developing a novel model to improve research and care for cancer survivors: a feasibility study [published online October 20, 2017]. J Cancer Edu.
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Last modified: August 10, 2023

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