Understanding Associations Between Patient-Level Factors and Participation in a Breast Cancer Clinical Trial

Although breast cancer (BC) clinical trials offer novel treatments, participating patients often do not represent populations seen in clinics. This study assessed how patient sociodemographics, attitudes, and knowledge about clinical trials may be associated with participation.

This cross sectional analysis used survey data collected August-September 2021 by Translational Breast Cancer Research Consortium (TBCRC) and December 2022 by Patient Advocate Foundation (PAF) among women with a BC diagnosis. Respondents reported BC clinical trial participation, Attitudes Toward Cancer Trials Scale, clinical trial knowledge, diagnosis age, race, education level, household income, employment status, and BC stage. Descriptive and bivariate analyses were conducted using Cramer's V or Cohen's d as effect sizes. Standardized total effects (b_Tot) were estimated using a prespecified Structural Equation Model with 0.1, 0.3, and 0.5 indicating weak, medium, and large magnitude, respectively.

Of 612 respondents, 26% were Black, Indigenous, or a Person of Color, 44% < Bachelor's degree, and 48% had incomes < $50,000. Respondents who reported trial participation (18%) more often had positive attitudes toward trials (mean 94 of 126, SD 19.3 vs. 86, SD 15.5; d = 0.48) compared to those not reporting participation. Positive attitude was associated with trial participation for both survey cohorts (TBCRC: b_Tot = 0.22, p = 0.0002; PAF: b_Tot = 0.13, p = 0.01). Furthermore, clinical trial knowledge was associated with attitudes (TBCRC: b_Tot = 0.27, p = < 0.0001; PAF: b_Tot = 0.15, p = 0.003).

Although we found that positive attitudes and high knowledge were associated with clinical trial participation, it is unknown if the trial itself directly affected this. However, trial enrollment may be increased and diversified via future interventions focused on promotion of positive attitudes toward clinical trials, potentially through increased trial education and knowledge.