Liquid biopsy tracks cancer

Volume 5, Issue 1, 2016


A liquid biopsy may help determine treatment options as cancer evolves.

A team of researchers from the Mayo Clinic Cancer Center and the Translational Genomics Research Institute (TGen) has reported that analyzing circulating tumor DNA (ctDNA) can track how a patient's cancer evolves and responds to treatment.

In a study published in Nature Communications in November 2015, Muhammed Murtaza, M.B.B.S., Ph.D., of the Mayo Clinic Cancer Center and TGen, and his colleagues, describe an extensive comparison between biopsy results and analysis of ctDNA in a patient with breast cancer. The researchers followed the patient during three years of treatment.

"When patients receive therapy for advanced cancers, not all parts of the tumor respond equally, but it has been difficult to study this phenomenon because it is not practical to perform multiple, repeated tissue biopsies," said Dr. Murtaza, one of the study's lead authors. "Our findings empirically show that ctDNA analysis from blood samples allows us to detect cancer mutations from multiple different tumor sites within a patient and track how each patient responds."

This type of blood test — known as a liquid biopsy — is less invasive, less costly and less risky than conventional tissue biopsies, which are considered minor surgeries.

Liquid biopsies also could be performed more frequently than a traditional biopsy, thus providing physicians with up-to-date information about how a patient's cancer might be changing. This, in turn, could help determine the best possible treatments to combat the cancer.