Related Experiment Video
Updated: Aug 27, 2026
Preparation of Peripheral Blood Mononuclear Cell Pellets and Plasma from a Single Blood Draw at Clinical Trial Sites for Biomarker Analysis
Published on: March 20, 2021
Racial and ethnic disparities in enrollment for clinical trials of poly (ADP-ribose) polymerase (PARP) inhibitors in
Parnian Kheirkhah Rahimabad1, Simran Sekhon2, Elizabeth John2
1Department of Radiation Oncology, University of Tennessee Health Science Center, Memphis, TN, USA. pkheirk1@uthsc.edu.
Background:
Poly (ADP-ribose) polymerase (PARP) inhibitors have shown promise in treating breast cancer with BRCA1/2 mutations, particularly triple-negative breast cancer (TNBC). There is limited data on the representation of different racial groups in PARP inhibitor clinical trials.
Methods:
We conducted a systematic review of phase II/III clinical trials using PARP inhibitors for the treatment of BRCA1/2-mutated breast cancers from 2016 to 2023, using PubMed, Embase, Scopus, CENTRAL, ClinicalTrials.gov, and Cochrane. Nine trials remained for analysis. Enrollment fraction (EF) was calculated by comparing the number of trial enrollees to the number of incident cancer cases. Logistic regression was used to determine the odds ratio (OR) of trial enrollment across racial groups.
Results:
Overall, the trials included a total of 2845 White, 136 Black, 83 Hispanic, 662 Asian, and 247 Other racial group patients. Other group was excluded from further analysis due to unspecified racial makeup. Among breast cancer patients of any type, EF was the highest for Asian (0.85%), followed by White (0.47%), Black (0.12%), and Hispanic (0.06%) patients. Comparing to White patients, the enrollment ORs were 0.26 for Black, 0.12 for Hispanic, and 1.80 for Asian (p < .001). Analyses were repeated excluding the Asian group, as these patients were recruited from Asian countries rather than the Asian American population. The ORs for Black and Hispanic patients remained the same and significant.
Conclusion:
Our results show the significant under-representation of Black and Hispanic patients in PARP inhibitor trials in the U.S., raising concerns about equity and the generalizability of trial outcomes for these populations.
