Colorectal cancer, a cancer of the large intestine or rectum, is now the leading cause of cancer deaths in people under 50 in the US, according to a study by the American Cancer Society (ACS). The study found that mortality and incidence have been increasing in those under 50 each year since 2013 and 2004, driven by advanced-stage disease. The rise in early onset diagnoses is also attributed to increased mortality among adults aged 50 to 64. This trend contrasts with the decreasing rate of new bowel cancer cases and deaths in adults ages 65 and over. The study also found that colorectic cancer cases were simultaneously rising in people over 50 and decreasing in 50- to 74-year-olds in 14 countries, including the U.S., Canada, Australia, and England. The researchers are unsure what is causing this trend, but noted that long-established risk factors for colorecedal cancer were identified based on cancer in older adults who were exposed to different risk factors than those in younger generations.