Topics in Pulmonary MedicineThe Liquid Biopsy, What is it, How is it Provided, and What is the Role of the PulmonologistDurrett, Sam MD*; Bowling, Mark R. MD*,†; Oliver, Aundrea L. MD‡ Author Information *Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine †Department of Cardiovascular Surgery, Division of Thoracic and Foregut Surgery ‡Department of Cardiovascular Sciences, Brody School of Medicine, East Carolina University, Greenville, NC None of the authors receive any funding for this work from the following organizations: National Institutes of Health (NIH), Wellcome Trust, Howard Hughes Medical Institute (HHMI). Disclosure: M.R.B. is a consultant for Medtronic Corporation, and Biodesix. The remaining authors declare that they have no conflicts of interest. Address correspondence to: Mark R. Bowling, MD, Department of Cardiovascular Surgery, Division of Thoracic and Foregut Surgery, Brody School of Medicine, East Carolina University, Greenville, NC 27834. E-mail: [email protected]. Clinical Pulmonary Medicine: March 2018 - Volume 25 - Issue 2 - p 33-38 doi: 10.1097/CPM.0000000000000249 Buy Metrics Abstract Non–small cell lung carcinoma represents the most common form of lung cancer, which itself is the cancer responsible for most deaths annually worldwide. In the advances toward personalized medicine in cancer care, the liquid biopsy is the most recent leap forward allowing treatment based upon driver mutations harbored within a patient. Cell free DNA (cfDNA) is shed from cells within the body, and the tumor cells are no different. This circulating tumor DNA can be sampled and tested for therapeutic and diagnostically actionable genes and gene mutations. Because of the relatively uncommon nature of these circulating tumor DNA, the available tests are designed to have very high sensitivity, with the tradeoff of a more modest specificity. The data supporting the major commercially available liquid biopsies are reviewed and summarized. The most common use of the liquid biopsy is to test for actionable mutations, but other uses include monitoring for disease progression and testing for resistance mutations in patients undergoing treatment. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.