Dr. Corcoran on Benefits/Limitations of Liquid Biopsies in GI Cancer

Ryan B. Corcoran, MD, PhD, clinical researcher, Massachusetts General Hospital, assistant professor of medicine, Harvard Medical School, discusses the benefits and limitations of using liquid biopsies in gastrointestinal (GI) cancer.

One of the biggest advantages to using liquid biopsies is for genotyping purposes is that it offers the opportunity to assess the tumor genome in a minimally invasive manner, Corcoran says, and that allows researchers to observe how the tumor biology evolves throughout treatment. Another benefit of using liquid biopsy over a standard tissue biopsy in GI cancer is that is the former can better capture the tumor heterogeneity, or different tumor cells residing in different lesions, which is important because different parts of the same lesion can develop different molecular mechanisms that can be clinically relevant.

On the other hand, cell-free DNA may miss molecular alterations that could involve protein or RNA changes, Corcoran notes. Sometimes patients simply do not shed enough tumor DNA, and in those cases, results from liquid biopsy can be unrevealing, even in the presence of disease.