UT Southwestern: physician and clinic drive cancer trial enrollment more than patient traits, in 200,000+ patients

Physician and oncology practice factors have greater influence over who is enrolled in advanced cancer clinical trials than measured patient characteristics such as age, cancer type and physical function. This is reported in a study led by UT Southwestern Medical Center researchers and published in JAMA Network Open on Nov. 10, 2026, according to newswise.com. newswise.comnewswise.comnewswise.comOpen source ↗

The team analyzed de-identified electronic health records from the Flatiron Health research database, covering adults treated for a broad range of advanced or metastatic solid tumors. The data came from 1,664 physicians at 107 oncology practices across the U.S., most of them in community settings rather than National Cancer Institute-Designated Cancer Centers. Trial participation was defined as receiving an investigational drug.

Enrollment concentrated in few physicians

Participation increased during the study period, but just over 5% of patients were enrolled in a trial. A total of 389 of 1,664 physicians (23%) accounted for 84% of all enrollments, and 21 of 107 practices (20%) accounted for 81%. Nearly a third of physicians enrolled no patients.

Characteristics of who treated a patient and where care was delivered explained more variation in participation than differences among patients. Patients had higher odds of participating when their physicians specialized in fewer cancer types, had recently enrolled other patients, or worked at research-active practices. Patients whose physicians focused on one or two cancer types had about four times the odds of joining a trial. newswise.comnewswise.comnewswise.comOpen source ↗

Disparities and proposed measures

Black patients were 26% less likely to participate than white patients. At practices serving the largest share of patients from low-income areas, the odds of participation were less than half of those at other practices.

The researchers outlined possible measures: pairing physicians new to trial enrollment with experienced mentors, assigning each clinic a dedicated research contact, providing staff support for trial-related testing, and using tools that match patients with suitable trials. Funders and trial sponsors could help build research capacity in clinics serving low-income communities and design simpler trials that smaller sites can run. Lead author Changchuan Jiang said that in the team's own safety-net clinics, patient navigation and physician engagement doubled enrollment of underrepresented patients.

The authors noted limitations. The database lacked information on whether individual patients were eligible for specific trials at a given time. Participation may also have been underestimated, because patients were counted only when they received a clinical study drug. newswise.comnewswise.comnewswise.comOpen source ↗