New Research Reveals Molecular Heterogeneity of Metastatic Gastroesophageal Cancer

REDWOOD CITY, Calif., Nov. 15, 2017 /PRNewswire/ -- Researchers from the University of Chicago, Dana-Farber Cancer Institute (DFCI), and Guardant Health, Inc. published new evidence of the genomic heterogeneity of advanced gastroesophageal cancers (GEA). The study suggests that patients with these cancers could benefit from targeted therapy based on the detection of biomarkers found with a comprehensive liquid biopsy, but that were absent from their primary tumor.

In a paper published in Cancer Discovery, researchers led by Daniel Catenacci, MD, of the University of Chicago, and Adam J. Bass, MD, of DFCI found that genomic alterations often vary between primary GEA tumors and metastatic lesions occurring elsewhere in the body. The study found that treatment-relevant genomic alterations in genes such as ERBB2 and EGFR were present in some metastases but absent from the primary tumor. As indicated by the investigators, these findings suggest that the common practice of performing DNA biomarker profiling on only the primary tumor, or a single metastatic site, may lead to suboptimal therapy selection in some clinical circumstances.

"The heterogeneity we have documented is a clear challenge to the current standard of care and has already changed the way I approach molecular testing for my patients with GEA," said Daniel Catenacci, MD, Assistant Professor of Medicine at the University of Chicago and one of the study's senior authors. "New strategies for selecting treatment are clearly needed and we will continue to investigate the benefit they can provide patients."  

The study also showed that the Guardant360® assay detected alterations found in circulating tumor DNA (ctDNA) that were not detected in the primary tumor tissue. These ctDNA-detected alterations were later confirmed to be present in metastatic sites, highlighting the genomic heterogeneity of the disease.

"In cancer, it's usually the metastases to the lung, liver, or brain that kill the patient. But it's hard to get tissue safely from these areas. This study shows that we can use ctDNA in the bloodstream to identify patients who acquire targetable alterations in the metastases," said Rick Lanman, MD, Guardant Health's Chief Medical Officer. "A tissue biopsy of a primary GEA tumor does not always tell the whole story, while a simple blood test may provide a more complete representation of metastatic disease without requiring multiple, invasive biopsies."

The Guardant360 assay is a comprehensive liquid biopsy that helps oncologists select the optimal treatment for advanced cancer patients. Guardant360 has been extensively validated and is supported by more than 15 prospective and retrospective clinical outcome studies. It is available in more than 30 countries.

About Guardant Health
Guardant Health is focused on conquering cancer by using its breakthrough blood-based assays, vast data sets, and advanced analytics. Using both molecular and digital tools, Guardant Health is addressing challenges across the cancer care continuum. The company has raised more than $500 million from leading investors. Its first product, the Guardant360 assay, came to market in 2014, and is now the most widely ordered comprehensive liquid biopsy commercially available and available in more than 30 countries. In 2016, it announced Project LUNAR, an effort to apply Guardant Health's technology platform to early detection, recurrence monitoring, and assessing minimal residual disease. Guardant Health and Guardant360 are registered trademarks of Guardant Health, Inc.

SOURCE Guardant Health