This computer-enhanced barium contrast X-ray shows colon cancer in red. Researchers have been trying to figure out what looks to be a decade-long rise in colon cancer among people younger than 50. Scott Camazine/Science Source hide caption toggle caption Scott Camazine/Science Source Shots - Health News Why Are More Young Americans Getting Colon Cancer? February 28, 2017 Data suggests that the rate of colon cancer among people under 50 is on the rise, but there are lots of possible explanations for that. Scientists say teasing out the truth will be tricky.