Uneven Distribution of Breast Cancer Clinical Trials Leaves Millions Without Access

A new study presented at the 2025 American Society for Clinical Oncology (ASCO) annual meeting in Chicago has revealed significant disparities in access to breast cancer clinical trials across the United States. The research, which analyzed active phase 2 and 3 interventional treatment trials as of September 2024, highlights the challenges faced by millions of women, particularly those with triple negative breast cancer (TNBC).

Geographic Disparities in Trial Availability

The study found that while most U.S. study sites offered multiple TNBC trials, approximately 37% of the sites assessed had no trials specifically for metastatic TNBC. This uneven distribution of clinical trials has left millions of women living in areas without access to potentially life-saving studies.

Dr. David Waterhouse, chair of ASCO's State of Oncology Care in America (SOCCA) Committee and one of the study's authors, emphasized the importance of changing "how we think about trials" to ensure greater accessibility. He stated, "It's an enormous thing."

Underrepresentation of Black Women in TNBC Trials

Despite being more likely to be diagnosed with TNBC, Black women remain underrepresented in clinical trials across the U.S. Interestingly, the study suggests that distance from trial sites may not be the primary reason for this disparity. Instead, the findings point to a more complex issue of trial availability and accessibility.

Addressing the Geographic Divide

Previous research by SOCCA, published last year, revealed that only 1 in 50 nonmetropolitan counties had broad trial portfolios, with 86% of those counties having no clinical trials at all. This stark divide between urban and rural areas underscores the need for a more equitable distribution of clinical trials.

Dr. Waterhouse acknowledged the difficulty in widening the geographic availability of clinical trials but emphasized that progress depends on prioritization and a willingness to change. As the pharmaceutical industry continues to grapple with these challenges, finding innovative solutions to expand trial access remains a critical priority for improving cancer care and outcomes across the United States.