In the first randomized trial of KRAS  (pronounced K-Rass) status and response to the targeted therapy panitumumab (Vectibix), researchers have confirmed that patients with advanced colorectal cancer benefit from the drug only if they have a normal form of the gene KRAS  present in their tumors, rather than a mutated KRAS  gene. KRAS  mutations are found in 30 to 50 percent of colorectal cancer patients. These are the latest findings in the field of "personalized medicine," which evaluate the potential...