Blood-based test detects cancer earlier, from the February 2013 Harvard Health Letter
A fundamental strategy in the war against cancer is to catch it early, long before it has spread. Harvard researchers are advancing the timeline for doing this with the development of a hand-held device that can spot signals of cancer in a drop of blood, reports the February 2013 Harvard Health Letter.
Many kinds of cells shed microvesicles, small pouches that pucker off cells' outer membrane. For decades, researchers have ignored microvesicles, thinking of them as a kind of cellular debris. But in the last few years, scientists have discovered that microvesicles contain DNA and other molecules, and that they can be linked to the cell type from which they came. Cancer cells shed a lot of microvesicles. "So you would easily find a million to several billion tumor microvesicles per milliliter of blood," says Dr. Ralph Weissleder, professor of radiology at Harvard Medical School.