Therapeutic Clinical Trial Eligibility and Enrollment among Women with Breast Cancer: Implications for Understanding Trial Disparities.

Introduction: Therapeutic clinical trials frequently lack diverse representation, hindering generalizability and exacerbating preexisting disparities in clinical outcomes. This study explored associations between breast cancer patient demographics, clinical trial eligibility, and enrollment in a National Cancer Institute (NCI)-designated cancer center.

Patients and methods: This prospective cohort study included patients with breast cancer screened for therapeutic clinical trials from July 2020 to January 2024. Eligibility was determined by the provider and study coordinator. Patient characteristics were abstracted from the electronic medical record. Rurality and neighborhood disadvantage were mapped by address using rural-urban commuting area codes and area deprivation index (ADI), respectively. Likelihood of eligibility and enrollment by race, rurality, and neighborhood disadvantage were evaluated using risk ratios (RR) and 95% confidence intervals (CIs) from modified Poisson regression models.

Results: Of 343 patients screened for therapeutic trials, the mean age was 56 years (SD 13), 33% were Black/other race, 22% lived in highly disadvantaged areas, and 16% in rural areas. Most patients were screened for one trial (87%). Overall, 54% of patients were eligible for trials, and of those, 58% enrolled. Similar likelihoods of eligibility and enrollment were seen by race and rurality. Though not significant, patients living in highly disadvantaged areas trended toward higher likelihood of enrollment (RR 1.24, 95% CI 0.99-1.55).

Conclusions: Over half of trial-eligible patients, even across race, rurality, or neighborhood disadvantage, enrolled, surpassing the national average. In contrast to national trends, there was higher enrollment among patients of higher ADI.