Molecular Residual Disease

About Molecular Residual Disease

Molecular residual disease (MRD) refers to the presence of tumor-specific DNA in the body after cancer treatment. These fragments of genetic information, known as circulating tumor DNA (ctDNA), are shed into the blood by solid tumors as part of the tumor growth cycle. Their presence may indicate that a tumor is present or likely to return. Solid tumors are typically undetected until they are advanced enough to be picked up by a medical image or physician examination. The detection of ctDNA at extremely low levels has the potential to provide crucial insights that may help discover cancer recurrence earlier and inform treatment decisions.


The Exact Sciences’ MRD solution is being designed to utilize a tumor-informed (bespoke) approach with whole exome or whole genome sequencing. This approach identifies somatic genetic alterations in DNA extracted from the patient’s tumor tissue and detects a subset of these mutations in ctDNA present in the patient’s blood. The MRD test that Exact Sciences is developing is intended for patients diagnosed with solid tumor malignancies to detect ctDNA before, during, and after cancer treatment. Such information may be used for guidance of adjuvant therapy decisions and/or for monitoring of cancer recurrence, in conjunction with other clinicopathological findings. The company estimates that more than 2 million patients1,2 in the United States alone could benefit from this type of MRD testing.




1 Incidence: Clarivate DRG 2021

2 Survival rates: ASCO publication, Dynamed and Cancer SEER