When David Lyon saw blood in his stool, he didn't think much of it. He was a fit 26-year-old who worked in a sheet metal shop. The spots were inconsistent, and he thought he might have just sustained an injury at work. But soon, Lyon had to admit something was wrong. He began to feel a sharp pain when he stood. It progressed to the point where he had to hunch over for relief. He went to an Erie, Pennsylvania, emergency room in July 2021, where a doctor recommended a colonoscopy. "Hearing this as a 26-year-old, I was like 'Yay, first colonoscopy, love this,'" Lyon said sarcastically. Three days later, Lyon was diagnosed with Stage IV colorectal cancer that had spread to his liver. His first reaction was anger."I stood up, I grabbed my hat, and like, threw it against the wall," Lyon said. "I just walked outside. I was seeing red, more or less."After calming down, Lyon decided to pursue aggressive treatment — but he didn't want to know the odds he faced.…