In the emerging era of personalized medicine, tissue biopsies play an increasingly important role in cancer management. A tiny sample, acquired by needle or by surgery, can provide not only material for routine diagnosis, but also reveal a universe of information about gene mutations driving tumor growth and point to highly targeted treaments. Trouble is, biopsies can be invasive, painful, and costly.

“There’s a big push for alternatives,” says David Polsky, MD, PhD, the Alfred W. Kopf, MD, Professor of Dermatologic Oncology at NYU Langone Health and a researcher at its Perlmutter Cancer Center. Dr. Polsky, for his part, is developing a series of novel blood tests, known as “liquid biopsies,” that can detect tumor DNA circulating in the bloodstream and help identify gene mutations linked to melanoma, the deadliest type of skin cancer. “Our tests could be useful for up to 75 percent of melanoma patients,” he says.

The majority of melanomas are caught early and can be surgically removed before they spread, thanks to routine skin exams, but for metastatic tumors, the new tests, developed in conjunction with Bio-Rad Laboratories, could eventually improve how the disease is managed. “The ability to capture DNA that’s shed in the blood allows us to overcome the wrinkle of inaccessible tissue,” says Iman Osman, MD, professor in the Ronald O. Perelman Department of Dermatology and director of the Interdisciplinary Melanoma Cooperative Group at NYU Langone. The long-term goal, Dr. Polsky explains, is to analyze a patient’s blood for tumor mutations at follow-up visits to determine as early as possible when a treatment has stopped working, cancer growth has resumed, and the patient needs to switch therapies.

Liquid biopsies hold profound implications for many other cancers as well, in particular lung cancer, the leading cancer killer among both men and women in the U.S. “Molecular diagnosis is an essential component of how we treat many lung cancers today because some medications target molecular changes within a tumor,” says Leena Gandhi, MD, PhD, director of the Thoracic Medical Oncology Program at NYU Langone. “We know that some tumors that have alterations evolve resistance to treatment and frequently need to be reanalyzed. The idea that we may be able to follow their progression with a simple blood draw rather than doing a more invasive procedure is a game changer.”