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William J. Gradishar, MD, FACP, FASCO
William J. Gradishar, MD, FACP, FASCO
Posted: Thursday, July 11, 2024
Racial disparities in survival between Black and White patients with specific types of metastatic breast cancer have spurred recent research into assessing the effect of race on targeted treatment. A study presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1017) highlighted differences in circulating tumor DNA between White and Black patients with estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer. Emily L. Podany, MD, of Washington University, St. Louis, and colleagues conducted this retrospective cohort study.
Data from 1,327 patients with metastatic breast cancer were analyzed in this study. Patients were categorized as ER-positive, progesterone receptor (PR)-positive, HER2-negative (n = 60 Black, n = 435 White) and ER-positive, PR-negative, HER2-negative (n = 24 Black, n = 237 White) using PR status. Patients were then evaluated by self-reported race and use of PIK3CA, CDK4/6, and mTOR inhibitors.
Overall findings revealed that Black patients with PIK3CA single nucleotide variants were significantly less likely to receive targeted therapy than White patients (5.9%, 1/17 patients vs 28.8%, 45/156 patients, Fisher’s exact test P = .045), whereas there was no difference found in the use of CDK4/6 or mTOR inhibitors. Further, none of the Black patients with PIK3CA mutations were enrolled in clinical trials vs 11.5% of White patients. Additionally, Black patients with ER-positive, PR-positive, HER2-negative tumors were more likely to have CCND1 copy number variation (odds ratio [OR] = 2.4, 95% confidence interval [CI] = 1.1–5.4, P = .030). When compared with White patients, Black patients with PR-negative tumors were more likely to have de novo metastatic disease (OR = 3.4, 95% CI = 1.1–10.8, P = .034) and GATA3 SNV (OR = 3.5, 95% CI = 1.04–11.6, P = .044).
Disclosure: Dr. Podany reported no conflicts of interest. For full disclosures of the other study authors, visit coi.asco.org.
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