ABSTRACT More than 70,000 adolescents and young adults (AYAs) are diagnosed with cancer in the United States (US) each year, and fewer than 10% enroll in clinical trials, reflecting far lower rates than seen in children and older adults. Yet AYAs with cancer who enroll in therapeutic clinical trials have improved survival and better adherence to long-term follow-up care during survivorship. In addition, clinical trial enrollment is essential to address inferior survival gains seen in recent decades for the A YA age group as a whole. Work in older adults has identified racial, ethnic, geographic, and socioeconomic disparities in clinical trial enrollment. Black and Hispanic adults are underrepresented in clinical trials relative to whites, as are patients in rural areas and with low incomes. Previous work to examine clinical trial participation among AYAs has failed to examine trial perspectives among underrepresented groups or the key barriers that stand in the way of their enrollment to therapeutic trials. The proposed study will evaluate disparities in enrollment to clinical trials among AYAs with cancer aged 12-29 years in 3 states: Louisiana, New Mexico, and Tennessee. All 3 states have among the highest poverty rates in the United States, with a mix of rural and urban geography and racially and ethnically diverse populations, including large numbers of Black and Hispanic AYAs as well as American Indian AYAs. We will focus on three key barriers to clinical trial enrollment among A YAs: structural barriers of trial availability and access, individual barriers such as financial concerns and beliefs about trials, and interpersonal barriers related to communication about trials between patients, family members, and oncologists. These areas have been identified in previous work in adults as remediable barriers to clinical trial enrollment with special relevance to racially, ethnically, geographically, and socioeconomically diverse populations. Our aims are: Aim 1: To assess AVA trial availability and access in 3 diverse states, including disparities by race, ethnicity, socioeconomic status, and geography. Using state cancer registry data and clinical trial availability data from ClinicalTrials.gov, we will identify available trials and AYA populations with limited trial access. Aim 2: To identify individual and interpersonal barriers to trial enrollment among AYAs with cancer, including differences by race, ethnicity, socioeconomic status, and geography. We will survey AYAs with cancer, caregivers, and oncologists to examine willingness to enroll in trials; interview American Indian AYAs to identify trial perspectives; and audiotape AYA-family-oncologist discussions to examine trial communication. Impact: At the end of this study, we will have identified key structural, individual, and interpersonal barriers to enrollment in clinical trials for A Y As in 3 states, including areas with special relevance to a racially, ethnically, socioeconomically, and geographically diverse population, and prioritized areas for intervention. Our next step will be the development of targeted interventions applicable across diverse settings to address identified barriers.

PROJECT NARRATIVE Adolescents and young adults (AYAs) with cancer enroll in therapeutic clinical trials at low rates, but limited research has evaluated the underpinnings of low trial enrollment in this vulnerable group, or the extent to which disparities in trial enrollment exist by race, ethnicity, socioeconomic status, and rural versus urban geography. The proposed study will evaluate disparities in enrollment to therapeutic clinical trials among AY As with cancer aged 12-29, with a focus on three key barriers: structural, individual, and interpersonal. We will examine availability and access to clinical trials for AYAs in 3 diverse states, Louisiana, New Mexico, and Tennessee, and use surveys and audiotaped encounters to examine individual and interpersonal barriers to trial enrollment, using results to develop high yield strategies for intervention in a diverse population of AYAs.