Racial Genomic Profiles of Primary and Metastatic Breast Cancer
In a study reported in a research letter in JAMA Network Open, Goel et al identified genomic differences among Black, Asian, and White patients with breast cancer and found that Black patients have fewer targetable actionable variants than White patients.
Study Details
The study included patients with breast cancer treated at Memorial Sloan Kettering Cancer Center and Dana-Farber Cancer Institute from 2014 to 2020 who had complete clinical and next-generation sequencing data in the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (GENIE). For the analyses, Hispanic White and non-Hispanic White patients were grouped as White. Among a total of 6,652 patients treated at the institutions during the period, there was complete sequencing in GENIE for primary breast cancer for 3.5% (7.1% Asian, 9.2% Black, 83.8% White) and for metastatic disease in 46.5% (6.0% Asian, 8.9% Black, 85.1% White).
Key Findings
Significant differences among patients with next-generation sequencing of primary breast cancer included the following findings:
- TP53 variations were identified in 62.0% of Black patients, compared with 37.2% of white patients (difference = 24.8%, 95% confidence interval [CI] = 19.0%–30.5%, P < .001) and 46.2% of Asian patients (difference = 15.8%, 95% CI = 7.3%–24.2%, P < .008)
- CDH1 mutations were found in 14.5% of White patients vs 7.7% of Black patients (difference = 6.8%, 95% CI = 3.5%–10.1%, P = .02).
Significant differences among patients with next-generation sequencing of metastatic disease included:
- CDH1 mutations were identified in 16.6% of White patients vs 9.9% of Black patients (difference = 6.7%, 95% CI = 2.7%–10.7%, P = .04)
- Genes with actionable variations were found in 6.4% of Black patients vs 9.1% of White patients (difference = −2.7%, 95% CI = −4.1% to −1.3%, P < .05)
- The greatest difference among individual genes occurred for PIK3CA targetable actionable variations, identified in 35.5% of White patients vs 26.6% of Black patients (difference = 8.9%, 95% CI = 3.1%–14.6%, P = .04).
The investigators stated: “Limitations [of the analysis] include the lack of breast cancer subtype data in GENIE and potential institutional differences in [next-generation sequencing] eligibility. However, although we are unable to assess genomic profiles by subtype, our focus on racial differences in mutations of actionable genes still highlights the importance of increasing minority enrollment in clinical trials and accessibility to precision oncology. This enables us to further explore breast cancer outcomes in the context of race-sensitive treatment paradigms and inform the novel discovery of new targetable and actionable genes in minority populations. The clinical implications of such data could help narrow the persistent racial gap in breast cancer outcomes.”
Neha Goel, MD, of the Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, is the corresponding author for the JAMA Network Open article.
Disclosure: The study was funded by awards from the National Institutes of Health and ASCO, Prostate Cancer Foundation, and others. For full disclosures of the study authors, visit jamanetwork.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.