Colon cancer is up among young adults; many don't think they're susceptible to it, and thus don't get screened for it

Cancer survivors pose for a photo at a colorectal-cancer awareness
installation. (Photo by Paul Morigi, Getty Images, via NatGeo) 

Colorectal cancer is no longer "an old people's disease;" it's hitting younger people more frequently, reports Tara Haelle of National Geographic. "One in five cases diagnosed today occurs in people younger than age 55, compared to one in 10 cases in 1995, according to a study published by the American Cancer Society. . . . There’s no clear explanation for this trend, but a new paper published in Science suggests a number of possible reasons, including environmental and genetic factors. Low screening rates and misdiagnosis in people who don’t suspect cancer likely also play a role."

The research also found more "diagnoses of advanced disease, which is particularly concerning because colonoscopies are 'a great tool for prevention and early detection of colorectal cancer in terms of screening that can actually detect and remove precancerous lesions,' says lead author Rebecca Siegel, senior scientific director of cancer surveillance research at the American Cancer Society," Haelle reports. "Survival rates are 90 percent if detected early enough."

Earlier screenings are part of the solution. Haelle notes that the U.S. Preventive Services Task Force now recommends that screenings begin at age 45 instead of 50, but Siegel said earlier screening is needed for those with risk factors "such as genetic risk scores, dietary lifestyle, obesity and family history," Haelle reports. "The most common symptoms for colorectal cancer in younger patients are abdominal pain; unexplained weight loss; changes in the frequency, size or appearance of stools; and rectal bleeding, which occurs in 46 percent of early-onset cases compared to 26 percent of cases in adults over age 50."