Liquid biopsy tests are gaining traction as a viable alternative to traditional diagnostic tests for cancer. These tests allow cancer care providers to screen patients for the presence of cancer indicators from a simple blood sample, instead of using a costly, painful and sometimes-risky surgery called a tumor tissue biopsy.

Screening earlier

Liquid biopsies have the potential to help detect cancer at earlier stages, provide a less-expensive and less-invasive way to monitor patients throughout treatment, provide more rapid results, and can help doctors make better decisions about which drugs are the best fit for patients.

Liquid biopsies represent an important new set of tools in a field called personalized medicine, which aims to provide safer and more effective treatments based on a patient’s individual biological characteristics.

“...liquid biopsies could be used instead of extensive imaging and invasive tissue biopsies for earlier detection of cancer and as a tool to guide cancer treatment decisions.”

Part of precision medicine

Personalized medicine is an evolving field in which physicians use diagnostic tests to determine which medical treatments will work best for each patient. By combining the data from those tests with an individual’s medical history, circumstances and values, health care providers can develop targeted treatment and prevention plans.

The use of diagnostic tests to help guide treatment decisions is becoming increasingly common. A recent report from a company called NextGxDx, for example, estimates that nearly 4000 new diagnostic tests were introduced to the market in 2015. In addition, more than 25 percent of all the medicines the U.S. Food and Drug Administration (FDA) approved in 2015 are associated with a diagnostic test identified on the product label. The FDA approved the first liquid biopsy test to detect a gene mutation associated with lung cancer earlier this year, and more are being considered for approval.

How the tests work

Liquid biopsies work by detecting DNA from circulating tumor cells or fragments of DNA shed by tumor cells into the bloodstream. A recent study of metastatic colorectal cancer patients showed that liquid biopsies could detect important gene mutations using this information 87.2 percent of the time.

As the U.S. and other health care systems shift away from one-size-fits-all, trial-and-error treatment approaches and toward personalized medicine, liquid biopsies could be used instead of extensive imaging and invasive tissue biopsies for earlier detection of cancer and as a tool to guide cancer treatment decisions.