Feasibility of Engaging High-Risk Breast Cancer Populations in Medical Cannabis Research: Multi-Site Recruitment Dynamics in the Cannabis-Associated Relief Effects (CARE) Study

Veronica Zhang Paley, MPP, MS
University of Miami

Co-authors: Veronica Z. Paley¹, Carmen Calfa¹, Veronica H. Lima², Eli Avisar¹, Priscila Barreto¹, Julie Bradley², Dejana Braithwaite², Tracy Crane¹, Richa Dawar¹, Milena Elimelakh¹, Zhigang Li², Erin Mobley², Lawerence Maximus Negret¹, Alejandra Perez¹, Isildinha M. Reis¹, Lisa Spiguel², Jose Suarez¹, Cristiane Takita¹, Juan Pablo de Rivero Vaccari¹, Frances Valdes¹, Yan Wang², Jennifer J. Hu^1
1University of Miami, ²University of Florida

Background: Prospective studies evaluating cannabinoid use during breast cancer treatment require diverse patient cohorts, as cannabis access, symptom burden, and potential therapy interactions vary. However, recruiting and retaining participants undergoing multimodal cancer treatment in longitudinal studies poses significant challenges. Therefore, evaluating the feasibility of recruitment strategies and cohort diversity and representativeness are crucial to ensure findings are generalizable.

Objective: This analysis aimed to evaluate recruitment trends, strategy optimizations, demographic, and unique clinical characteristics of participants enrolled in the Cannabis-Associated Relief Effects (CARE) study.

Methods: CARE is a prospective cohort study investigating the benefits and harms of medical cannabis among breast cancer patients during and after systemic therapy. Participants are recruited across three sites: University of Miami (UM), University of Florida (UF) Gainesville, and UF Jacksonville. Strategies to identify potentially eligible participants to approach for recruitment included electronic health record (EHR) screening, discussion at tumor board, and provider referrals, with recruitment occurring in-person at clinic visits. Throughout the study, strategy optimization included expanding eligibility criteria, Spanish-translated materials, and EHR workflows. We analyzed monthly enrollment from March 2025–July 2026 alongside baseline demographics and tumor characteristics.

Results: As of July 16, 2026, cumulative enrollment reached 131 participants. Following strategy optimizations, average monthly enrollment surged from 4.7 participants (March–December 2025) to 12.0 (January–July 2026), reaching 15-16 participants monthly from April to July 2026. Among participants at baseline (n=89), 72% were White, 21% Black, 34% Hispanic, and 13% under age 40. Diversity varied markedly by site: Black participants comprised 41% of UF-Jacksonville, 26% of UF-Gainesville, and 10% of UM, while Hispanic participants represented 61% of UM. Clinically (n=87), 11% had stage III and 9% stage IV disease. Notably, 37% overall had triple-negative breast cancer (TNBC), with marked site variations: 82% at UF-Jacksonville, 33% at UM, and 17% at UF-Gainesville.

Discussion & Conclusion: Recruitment strategies, coupled with real-time optimization, successfully facilitated enrollment of a high-risk, diverse breast cancer cohort. Expanding eligibility criteria and strategies accelerated enrollment. Non-Hispanic Black women face disproportionately high TNBC rates; notably, our cohort-particularly at UF-Jacksonville (82%) and UM (33%)-demonstrates exceptional representation of TNBC populations. The study team will continue to monitor recruitment and retention of participants during and following systemic therapy completion, while maintaining engagement with the clinical teams to support enrollment and retention. This study provides the real-world feasibility of recruiting women with breast cancer undergoing systemic therapy for participation in a complex, longitudinal quality of life study.