Guardant Health presented promising data for its blood-based Shield™ Multi-Cancer Detection (MCD) test at the 2025 American Association for Cancer Research (AACR) annual meeting, demonstrating high specificity and clinically meaningful sensitivity across ten tumor types.
The methylation-based Shield MCD test achieved 98.5% specificity and 60% overall sensitivity in detecting cancer from a simple blood draw. Notably, the test showed 74% sensitivity across the six most aggressive cancers, including esophageal-gastric, hepatocellular, lung, ovarian, and pancreatic cancers—malignancies defined by having the shortest survival rates.
"There are still many types of cancer that are difficult to detect with existing technologies until the late stages. This strong data reinforces the potential of the Shield test to detect multiple cancers earlier through a simple blood draw," said AmirAli Talasaz, Guardant Health co-founder and co-CEO.
Study Design and Key Findings
The blinded case-control study evaluated samples from 778 individuals aged 40-78 years (median age 62) with either a known cancer diagnosis or who self-reported being cancer-free. The study population was 55% female and 79% white.
Across the ten cancer types evaluated, sensitivity varied significantly by cancer type, ranging from 96% for esophageal-gastric (stomach) cancer to 21% for prostate cancer, all at 98.5% specificity. The test also demonstrated 89% accuracy for primary or secondary cancer signal of origin (CSO) prediction—a critical feature that could help guide diagnostic evaluation by indicating the likely location of a detected cancer.
"Impressively, this initial cohort analysis of the Shield MCD test met overall performance expectations, with particularly strong sensitivity in the six most aggressive cancers for which early detection is key," said William Greenleaf, Ph.D., study co-author, consultant for Guardant Health, and professor of genetics at Stanford University School of Medicine.
NCI Vanguard Study Selection
Based on these promising results, the National Cancer Institute (NCI) selected the Shield MCD test for inclusion in its highly anticipated Vanguard Study, which will evaluate emerging multi-cancer detection technologies.
The selection represents a significant milestone for Guardant Health and validates the potential clinical utility of the Shield MCD test in cancer screening programs. Multi-cancer detection tests aim to complement existing single-cancer screening methods by detecting multiple cancer types with a single blood draw.
Guardant's Broader Precision Oncology Platform
The Shield MCD test is part of Guardant Health's broader Guardant Infinity™ smart liquid biopsy platform. At AACR 2025, the company presented a total of 18 abstracts, including four oral sessions, showcasing advances in multi-cancer detection and multiomic precision oncology testing.
Other presentations highlighted analytical validation of Guardant's new tissue profiling assay with integrated multiomics, showing high success rates with minimal tissue input, and new methylation-based applications for liquid biopsy, including molecular subtyping of lung and breast cancer.
"We look forward to sharing new data demonstrating the tremendous potential of the Guardant Infinity smart liquid biopsy platform to provide researchers and healthcare providers with a more complete picture of cancer, including genomics, epigenomics and more," said Helmy Eltoukhy, Guardant Health chairman and co-CEO. "This multidimensional view of cancer biology is enabling advances in precision oncology ranging from blood-based multi-cancer detection to identification of novel biomarkers that can help bring the next generation of cancer therapeutics to patients sooner."
Potential Clinical Impact
Early cancer detection remains a critical challenge in oncology, with many aggressive cancers diagnosed only at advanced stages when treatment options are limited and outcomes poor. Blood-based multi-cancer detection tests like Shield MCD could potentially transform cancer screening by enabling earlier detection through minimally invasive means.
The ability to detect multiple cancer types with a single blood test, combined with accurate prediction of the cancer's origin, could streamline diagnostic workups and potentially reduce the time to diagnosis and treatment initiation.
As the Shield MCD test advances through further validation in the NCI's Vanguard Study, healthcare providers and patients will be watching closely to see if this technology can deliver on its promise to detect cancers earlier when treatment is more effective, potentially reducing cancer mortality through earlier intervention.
