A blood test five years after breast cancer treatment helped identify some women who were more likely to relapse, long before a lump or other signs appeared, a preliminary study found. It was the largest experiment so far to use these tests, called liquid biopsies, for breast cancer. Results suggest they someday may help reveal which women need longer preventive therapy and which ones can be spared it, per the AP. "It could be providing an early warning sign" for some women that cancer is returning, said Dr. Joseph Sparano of Montefiore Einstein Center for Cancer Care in New York. On the other hand, "if you had a negative test, there was a 98% chance you would not have a recurrence in the next two years" and perhaps could skip further treatment, he said.
Sparano led the study and gave results Friday at the San Antonio Breast Cancer Symposium. The test—CellSearch, sold by Menarini-Silicon Biosystems—looks for stray cancer cells in the blood. Breast cancer survivors may be tempted to rush out and get it, but doctors say it's too soon for that. Although it's been used for about a decade to monitor certain patients with advanced cancer during treatment, its value for helping to predict breast cancer relapse risk is not well established, and insurers won't pay the $600 to $900 tab. The new study, which involved 547 women, could spur more research. Among those with estrogen-fueled disease, 5% had cancer cells in the blood test, and they turned out to have a 22-fold higher risk of recurrence within roughly two years compared to women whose blood test was negative.