Liquid biopsies are offering earlier and easier insights into patients' cancers, the Associated Press reports. These tests capture bits of cancer cells or DNA that have broken off from the tumor and are circulating in the blood.
Just a few years ago, the AP notes, the approach was limited to research studies, but it is now being used more often in the clinic. It's especially used for patients whose tumors are hard to access or the site of which is unknown and for patients whose treatment no longer works.
Gurpaul Bedi underwent one at the University of Texas MD Anderson Cancer Center to gauge his metastatic colon, while Carole Linderman in Philadelphia underwent one that caught a recurrence of her breast cancer.
"Had this test not been available, we may not have known I had cancer on my spine until symptoms showed up," Linderman tells the AP, adding that that might have been too late to receive the treatment she needed.
The AP says the potential for liquid biopsies is tremendous, but there isn't yet enough data to show that they'll be cost effective. One such test costs about $5,400, though some insurers cover it for some patients. But it could eliminate other costs like the $10,000 price tag of a traditional lung biopsy or spending on drugs that won't work, the AP says. However, one of the promises of liquid biopsies is that they can be used to monitor patients over time — meaning more tests, the AP adds.
But other liquid tests may come along. The AP notes that researchers are working to develop a way to detect tumor DNA in urine.