In the Massachusetts General Hospital in Boston in the US, scientists have made a leap forward in the search for cancer treatments. They have developed a blood test which is so sensitive that it can spot a single cancer cell amongst a billion healthy ones.
Doctors believe that stray cancer cells in the blood mean that a tumour has spread or is likely to, so a test that can identify such cells is a real revolution. This test could help doctors choose treatments for cancers of the breast, prostate, colon and lung. It could also ultimately lead to better cancer screening programmes.
Doctor Minetta Liu, a breast cancer specialist from Georgetown University said: “We all recognise that the current tools that we have are not that exact and no matter what we try to do to predict how someone may do, we’re not always right. So we are all clamouring for tools that will help us improve identifying patients who need treatment or who can finish treatment earlier, or do we need to be more aggressive in treatment?, Or is this never going to come back? So to have particularly a test like this, which is a blood test, as opposed to putting a patient in a scanner with an IV and more contrast.”
The test uses a microchip covered with 78,000 tiny posts, like bristles on a hairbrush. The posts are coated with antibodies that bind to tumour cells. When blood is forced across the chip, healthy cells ping off the posts like balls in a pinball machine. But cancer cells stick, and stains make them glow so researchers can count them and isolate them for study.