For these 10 cancer specialists to lower their chances of getting the disease – they practice what they preach. Axel Grothey, MD, oncologist at Mayo Clinic, says a colonoscopy is the gold standard for detecting colon cancer. He even literally adds some flavor to the exam prep. “When I have to drink the liquid provided to speed things up down there, I mix it with lemon-lime Kool-Aid. It makes it taste so much better (don't use anything that's a stronger color, since it can stain your colon),” said Grothey.