For Immediate Release: Wednesday, October 21, 2026, 2:40 p.m. U.S. Eastern Time
Media Contact: Evelyn Mantegani, +1 240-833-2014, [email protected]
Presented By: Emily Russell, PhD, LabCorp
Rockville, Md. – Cancer biomarkers and the likelihood of identifying clinically useful genetic variants differ across ancestry groups, according to a large study of nearly 29,000 patients. The findings could help researchers better understand disparities in access to immunotherapy and targeted treatments.
Researchers from Labcorp analyzed 28,870 patients who received genomic testing during routine cancer care. The team used a validated machine learning workflow to infer genetic ancestry from germline variants detected through tumor DNA sequencing. Patients represented eight ancestry categories, enabling researchers to compare cancer types, immunotherapy biomarkers, and the clinical actionability of genetic variants across populations.
The analysis reproduced known epidemiological patterns, including higher proportions of breast cancer among patients with African ancestry and gastrointestinal cancers among several non-European ancestry groups. It also identified potential new associations, such as a higher prevalence of brain and nervous system cancers among patients with Admixed American ancestry.
Biomarkers that can influence immunotherapy eligibility also varied. Patients with European ancestry had higher proportions of tumors with high tumor mutational burden or high PD-L1 levels, while patients with African ancestry had a modestly higher prevalence of microsatellite instability-high tumors. These differences may partly reflect variation in cancer types across groups.
Patients with African ancestry also had the greatest burden of variants of uncertain significance, while the Central Asian/Siberian group had the lowest rate of clinically actionable findings. The researchers say incorporating genetic ancestry into precision oncology studies may help identify inequities and support more representative, effective cancer care.
About the American Society of Human Genetics (ASHG)
The American Society of Human Genetics (ASHG) is the leading global organization advancing the science of human genetics and genomics. Representing nearly 8,000 researchers, clinicians, genetic counselors, educators, and other professionals, ASHG drives progress in understanding the human genome and its role in health and disease. The Society fosters innovation and collaboration through its flagship events and publications—including the ASHG Annual Meeting and its peer-reviewed journals The American Journal of Human Genetics and Human Genetics and Genomics Advances. ASHG also champions science advocacy, supports the next generation of genetics professionals, and promotes responsible policies and public engagement in genetics. Learn more at www.ashg.org.
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