Liquid Biopsy Blood Test: What It Would Mean 

“it will give us a non-invasive, or a non-painful way of monitoring a cancer, following a cancer day to day, week to week, without having to do repeat biopsies,” Haber said. 

Cancers can shed cells that circulate in the bloodstream at extremely low levels, LaPook reports. This technology finds them by passing a blood sample through a microchip coated with antibodies that bind only to the cancer cells. 

MGH Cancer Center’s new test can recognize a single cancer cell among a billion normal ones. 

“It would be most helpful for patients with prostate, bladder, colon, kidney and lung cancer, in addition to breast cancers,” said Dr. Christopher Logothetis with the the University of Texas MD Anderson Cancer Center. “In many ways, it serves as a liquid biopsy.” 

In addition to detecting recurrences sooner, the test may allow doctors to examine the cancer cell itself and tailor therapies to a particular patient. 

Four sites across the country are beginning to use the new test on patients. The research is supported by a million grant from "stand up to cancer." 

“If we only had a way to of measuring cancers as they are being treated, seeing how they respond relatively quickly and adjusting our treatment depending on how the treatment responds, then it would be a different day for treating cancer,” Haber said. 

If all goes well, the test is expected to become widely available in three to five years.