Mount Sinai researchers have validated for the first time that a simple blood test called a liquid biopsy could be a better predictor of whether cancer immunotherapy will be successful for a patient with lung cancer than an invasive tumor biopsy procedure. Their study was published in the Journal of Experimental & Clinical Cancer Research in June.
The liquid biopsy tests for a biomarker of PD-L1, a protein and target for a type of immunotherapy called checkpoint inhibitors, which helps the patient’s immune system attack and kill cancer cells. This study showed that testing the blood of lung cancer patients for the PD-L1 biomarker gave more accurate predictions of the response and survival for patients with lung cancer than testing for PD-L1 in tissue from lung cancer biopsies, the current standard of care.
The biomarker in blood, named EV PD-L1, comes from extracellular vesicles, which are particles shed from tumor cells. A decrease of PD-L1 in extracellular vesicles in blood could therefore become a useful test to predict which patients with non-small-cell lung cancer could benefit from immunotherapy.
“These results will have an impact in the search for biomarkers to predict for immunotherapy outcome in patients with lung cancer as no truly reliable biomarkers have been found yet,” said senior author Christian Rolfo, MD, PhD, MBA, Professor of Medicine (Hematology and Medical Oncology) at the Icahn School of Medicine at Mount Sinai, Associate Director for Clinical Research in the Center for Thoracic Oncology at The Tisch Cancer Institute, and President of the International Society of Liquid Biopsy. “If validated in larger prospective cohorts of patients, as we are working on now, this protein could complement or substitute for the tissue PD-L1 as the standard of care in these and other types of tumor patients receiving immunotherapy, especially because it is minimally invasive and can be repetitive during treatment, being able to detect changes in the tumor during the treatment in real time.”
Researchers collected blood samples from two cohorts of 33 and 24 patients with non-small-cell lung cancer receiving immune-checkpoint inhibitors before and at the ninth week of treatment. They also included a group of 15 patients receiving chemotherapy as controls. Extracellular vesicles were isolated from blood samples and the protein expression of PD-L1 was measured in each group at both time points. Researchers also measured imaging scans of patients’ tumors before treatment and evaluated them with an innovative imaging technology called radiomics to create a full model for prediction of immunotherapy response.
This study, led by Dr. Rolfo, included collaboration of experts in radiomics and medical oncology from the United States, Mexico, and Italy.
About the Mount Sinai Health System
The Mount Sinai Health System is New York City’s largest academic medical system, encompassing eight hospitals, a leading medical school, and a vast network of ambulatory practices throughout the greater New York region. Mount Sinai advances medicine and health through unrivaled education and translational research and discovery to deliver care that is the safest, highest-quality, most accessible and equitable, and the best value of any health system in the nation. The Health System includes approximately 7,300 primary and specialty care physicians; 13 joint-venture ambulatory surgery centers; more than 415 ambulatory practices throughout the five boroughs of New York City, Westchester, Long Island, and Florida; and more than 30 affiliated community health centers. The Mount Sinai Hospital is ranked on U.S. News & World Report’s “Honor Roll” of the top 20 U.S. hospitals and is top in the nation by specialty: No. 1 in Geriatrics and top 20 in Cardiology/Heart Surgery, Diabetes/Endocrinology, Gastroenterology/GI Surgery, Neurology/Neurosurgery, Orthopedics, Pulmonology/Lung Surgery, Rehabilitation, and Urology. New York Eye and Ear Infirmary of Mount Sinai is ranked No. 12 in Ophthalmology. Mount Sinai Kravis Children’s Hospital is ranked in U.S. News & World Report’s “Best Children’s Hospitals” among the country’s best in four out of 10 pediatric specialties. The Icahn School of Medicine is one of three medical schools that have earned distinction by multiple indicators: ranked in the top 20 by U.S. News & World Report’s “Best Medical Schools,” aligned with a U.S. News & World Report “Honor Roll” Hospital, and No. 14 in the nation for National Institutes of Health funding. Newsweek’s “The World’s Best Smart Hospitals” ranks The Mount Sinai Hospital as No. 1 in New York and in the top five globally, and Mount Sinai Morningside in the top 20 globally.