A common enzyme that is easily detected in blood may predict how well patients with advanced kidney cancer will respond to a specific treatment, according to doctors at Duke Cancer Institute. The finding, published online Monday, Aug. 13, 2012, in the Journal of Clinical Oncology, could lead to the first blood test to determine the best treatment for late-stage kidney cancer. “Being able to direct these patients to a treatment we know will help them would be a major advancement in their care,” said Andrew Armstrong, M.D., ScM, associate professor of medicine and surgery at Duke and lead author of the study. “At the same time, patients who would not benefit from the treatment would be spared from undergoing a drug regimen with potential side effects that could diminish their quality of life.”