Guardant’s blood test tracks microsatellite instability status on par with tissue biopsy in new study

A study of nearly 1,000 samples showed that Guardant Health’s blood test was able to determine microsatellite instability status about as accurately as tissue-based biopsies, potentially providing an easier way to predict a cancer patient’s response to immunotherapy across multiple types of solid tumors.

Known as MSI, the genetic biomarker serves as evidence that the body’s mechanism for fixing small errors in DNA is not functioning correctly, leaving them more vulnerable to cancer-causing mutations.