Strategies for increasing accrual in cancer clinical trials: What is the evidence?

INTRODUCTION: Despite the importance of clinical trial participation among cancer patients, few participate-and even fewer patients from ethnic and racial minoritized groups. It is unclear whether suggested approaches to increase accrual are successful. We conducted a scoping review to identify evidence-based approaches to increase participation in cancer treatment clinical trials that demonstrated clear increases in accrual. Notably, more stringent than other published reviews, only those studies with comparison data to measure a difference in accrual rates were included. METHODS: We searched PubMed/MEDLINE, Embase, CINAHL, and Web of Science for English-language articles published from January 1, 2012, to August 8, 2022. Studies were included if they were conducted in the United States, described single or multicomponent interventions, and provided data to measure accrual relative to baseline levels or that compared accrual rates with other interventions. RESULTS: Sixteen articles were included: six with interventions addressing patient barriers, two addressing provider barriers, seven describing institutional change, and one describing policy change. Key themes emerged, such as a focus on patient education, cultural competency, and building the capacity of clinics. Few studies provide comparative accrual data, making it difficult to identify with certainty any effective, evidence-based approaches for increasing accrual. Some patient- and system-level interventions studies showed modest increases in accrual primarily through pre-post measurement. CONCLUSION: Despite an extensive body of literature about the barriers that impede cancer treatment trial accrual, along with numerous recommendations for how to overcome these barriers, results reveal surprisingly little evidence published in the last 10 years on interventions that increase accrual relative to baseline levels or compared with other interventions. As clinical trials are a primary vehicle through which we improve cancer care, it is critical that evidence-based approaches are used to inform all efforts to increase accrual. Strategies for increasing participation in cancer clinical trials must be developed and rigorously evaluated so that these strategies can be disseminated, participation in trials can increase and become more equitable, and trial results can become more generalizable.

Veterans with blood cancers: Clinical trial navigation and the challenge of rurality.

PURPOSE: The proportion of cancer patients who participate in clinical trials (CTs) remains low, despite an understanding of barriers to enrollment. The barrier of rural residence is relevant to Veterans, who more commonly live in rural areas than non-Veterans. In this exploratory study, we aimed to examine geographic factors that could impede CT enrollment and to improve access to CTs for Veterans. METHODS: To assess the influence of rurality on the availability of CTs, we performed simulated searches using The Leukemia & Lymphoma Society's Clinical Trial Support Center (LLS CTSC) database. The LLS CTSC provides free CT education and navigation. In the second part of this study, we offered Veterans with blood cancers who received care at the Durham, Salem, Clarksburg, Sioux Falls, and Houston Veterans Administration (VA) Medical Centers referral to the LLS CTSC. FINDINGS: In simulated searches, we found significantly lower numbers of CTs open to enrollment in rural areas, compared to urban areas. In actual referrals, 33 Veterans were referred to the LLS CTSC, of which 15 (45%) lived in rural areas. Three Veterans enrolled in CTs. Patients declined referral or did not enroll in CTs for various reasons, including a desire to maintain care within the VA and/or to initiate therapy quickly. CONCLUSIONS: We identified "clinical trial deserts," which might hinder access and reduce CT participation for rural Veterans. Referral to the LLS CTSC promoted CT education and enrollment among a highly rural cohort of Veterans receiving care in the VA system.

Overcoming Barriers to Clinical Trial Participation: Outcomes of a National Clinical Trial Matching and Navigation Service for Patients With a Blood Cancer.

PURPOSE: There are numerous barriers to cancer clinical trial participation in the United States. This paper describes the approach and outcomes of The Leukemia & Lymphoma Society's Clinical Trial Support Center (CTSC), whose nurse navigators assist patients with a blood cancer and their oncologists by identifying all appropriate trials based on clinical data and patient preference, facilitating informed and shared decision making, and minimizing enrollment barriers. METHODS: Data on patients served from October 2017 to October 2019 were analyzed using bivariate and multivariate analyses to determine demographic and clinical characteristics associated with enrollment. Reasons for nonenrollment were examined. RESULTS: The CTSC opened 906 patient cases during this time frame. Among all US patients with a closed case (n = 750), the clinical trial enrollment rate was 16.1%. Among those with a known enrollment outcome after a trial search (n = 537), the enrollment rate was 22.5%. Multivariate analysis controlling for variables significant in bivariate analyses (insurance, treatment status, Eastern Cooperative Oncology Group performance status, and urban or rural residence) revealed that patients with Medicaid were less likely to enroll than those with private or commercial insurance (adjusted odds ratio, 0.054; CI, 0.003 to 0.899), and patients in treatment or maintenance were less likely to enroll than those relapsed or refractory to most recent therapy (adjusted odds ratio, 0.312; CI, 0.139 to 0.702). Primary reasons for nonenrollment were preference for standard of care (66.3%) and patient passed away (16.1%). CONCLUSION: The CTSC is an effective, replicable model for addressing multilevel barriers to clinical trial participation. The findings highlight the need to increase opportunities for trial participation sooner after diagnosis and among patients with Medicaid.