Your doctor may one day be able to use a simple blood test to find out if you have cancer. Researchers from Johns Hopkins University reported in the January 19 issue of Science that they have developed a blood test that can spot early signs of cancer. The researchers screened blood for DNA and proteins related to eight different types of cancer. They were able to identify early cancers from more than 1,000 patients with different types of cancer that had not yet spread. Overall, the test found 33% to 98% of cancers, depending on tumor type. The test also had a low false-positive rate. When tested on more than 812 healthy individuals, less than 1% of results reported the presence of cancer in people who actually didnt have it. In some cases, researchers were also able to narrow what type of cancer an individual had based on the blood sample. This work may eventually lead to the development of a screening tool that can help detect cancers at an early stage, when they are most treatable.(Harvard Womens Health Watch)