Adults in the United States are dying from colon and rectal cancers at an increasing rate about age 50, when they should just be beginning screenings, according to a new study from the American Cancer Society. Since routine screening is generally not recommended for most adults under 50, the cancers found in younger adults are often in advanced stages and more deadly, said Dr. James Church, a colorectal surgeon at the Cleveland Clinic in Ohio. Church, who was not involved in the new study, said he has seen this trend in death rates up close. Last year, on separate occasions, Church saw two 36-year-olds with stage IV colon cancer, he said. In both of those patients, who had no relation to each other, the cancer spread to their livers, making it so he couldn’t operate. Both died, he said. “They both had young families, both little girls, and they lost their father in one case and their mother in the other, forever, because of this nasty disease when it’s advanced,” Church said. “It makes a big impact on me, and it makes me keenly interested in trying to solve this issue,” he said. “Everybody in colorectal surgical circles is seeing increased incidence of colon cancer in the young, defined as younger than 50.” The new study, published Tuesday in the medical journal JAMA, is a followup to one that found that incidence rates of colon and rectal cancers are rising in American adults under 50, the recommended screening age. According to the previous study, adults born in 1990 could have twice the risk of colon cancer and four times the risk of rectal cancer at the same age had they been born in 1950. The reason for the rise in both incidence and death rates remains unclear. “We’ve known that there’s this increasing trend in people under 50 for incidence, but a lot of people were saying, ‘Hey, this is good news. This means people are getting more colonoscopies, and cancer’s being detected earlier,’ ” said Rebecca Siegel, an epidemiologist at the American Cancer Society and lead author of the new study.