Blood test helped detect cancer before symptoms, study finds

MARILYNN MARCHIONE AP Chief Medical Writer For the first time, a blood test has been shown to help detect many types of cancer in a study of thousands of people with no history or symptoms of the disease. The test is still experimental. Even its fans say it needs to be improved and that Tuesday's results are not ideal. Yet they show what benefits and drawbacks might come from using these gene-based tests, called liquid biopsies, in routine care -- in this case, with PET scans to confirm or rule out suspected tumors. "We think that it's feasible," said Nickolas Papadopoulos, a Johns Hopkins University scientist who helped develop the test. Using it along with standard screening methods "doubled the cancers that were detected" in the study, he said. But the test also missed many more c