'Liquid biopsies' alert advanced breast cancer patients when new drugs are needed

New research suggests that blood tests known as “liquid biopsies” can improve the treatment of some people with metastatic breast cancer and help their tumors remain under control for more than a year.

New research suggests that blood tests known as “liquid biopsies” can improve the treatment of some people with metastatic breast cancer and help their tumors remain under control for more than a year.

For many, it’s been a long time coming: More than a decade ago, researchers and investors predicted that liquid biopsies — which are sensitive enough to detect tumor cells and DNA in the blood — would be “game changers” in the realm of cancer.

Although liquid biopsies haven’t replaced standard cancer screening methods like mammograms and colonoscopies, the new study and others like it demonstrate that the blood tests can help doctors monitor cancer and help them select treatments most likely to work.

Liquid biopsies are so sophisticated that they can detect minuscule bits of DNA that have leaked out of tumor cells and are floating freely in the blood. The most sensitive liquid biopsies, like those used in the new study, go one step further, detecting ominous changes in key proteins in cancer cells.

The research — published Sunday in The New England Journal of Medicine and presented at the American Society of Clinical Oncology’s annual meeting in Chicago — focused on people whose breast cancers are fueled by estrogen. The most effective treatment for this type of advanced disease includes drugs designed to target specific proteins in breast cancer cells. If those proteins mutate, the drugs stop working, and it’s only a matter of time before the cancer begins growing again.