Circulating tumor DNA has been proven to accurately track how cancer evolves and responds to therapy for the first time. The results of this proof-of-principle study were published today in Nature Communications.
The study involved a patient with metastatic breast cancer. Over 3 years, a team of researchers from the University of Cambridge (UK) isolated surgical samples and also blood samples from the patient, from which they analyzed circulating tumor DNA and compared with DNA from the surgical biopsies.
Upon comparison, it was established that the circulating DNA matched up with biopsy DNA, displaying the same pattern and timing of genetic changes over time as the cancer evolved and responded to therapy. Analysis of the circulating DNA was also able to distinguish between the various secondary cancers and examine how each was responding to treatment.
“This definitively shows that we can use blood-based DNA tests to track the progress of cancer in real time. The findings could change the way we monitor patients, and may be especially important for people with cancers that are difficult to reach, as taking a biopsy can sometimes be quite an invasive procedure,” commented author Carlos Caldas, group leader at the Cancer Research UK Cambridge Institute.
Further work will be carried out to determine if analysis of free tumor DNA can be utilized to map disease progression in other patients and other disease types.