Colorectal Cancer Rates Rising Among Young Folks

A new study found that despite declining for adults 55 and older, rates of colon and rectal cancer are spiking among young and middle-aged Americans.
The study results are sparking discussion about whether screening for colon cancer should start earlier.
The study, published last week in the Journal of the National Cancer Institute, found between the mid-1980s and 2013, colon cancer rates increased about 1 percent to 2 percent annually for people in their 20s and 30s. Rates for middle-aged adults rose, too, but at a slower pace.
Rectal cancer rates have climbed even faster, at about 3 percent per year for people in their 20s and 30s and 2 percent each year for people ages 40 to 54. This adds up to startling statistics: Three in 10 new cases of rectal cancer now are diagnosed in patients younger than 55. That’s double the proportion in 1990. By contrast, rectal cancer rates in adults age 55 and older have declined for 40 years.
American Cancer Society researcher and study lead Rebecca Siegel said earlier studies signaled a growing incidence of colorectal cancer among Gen Xers and millennials. But the size of the increase “was just very shocking,” she said.
The study didn’t explain the reason for the increase. But Siegel suggested one explanation might be a complex interaction between the same factors contributing to the current obesity epidemic in this country: a more unhealthy high-fat diet, a sedentary lifestyle, excess weight and low fiber consumption.
For the new study, researchers looked at more than 490,000 people ages 20 and older who received diagnoses of invasive colorectal cancer between 1974 and 2013, focusing specifically on years of birth and five-year age groups. Comparing different generations at similar ages, it found those born around 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer as people born around 1950.
This confirms what many doctors report seeing among their younger patients. “I have many patients in their 30s and 40s, and some in their 20s,” Nilofer Azad, M.D., an oncologist at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, told The Washington Post. “The vast majority of young people won’t get colorectal cancer, and their symptoms are more likely not the disease.”
Dr. Azad was not involved in the new study, but she stressed that young people who have symptoms—including rectal bleeding or a change in bowel habits—“push their doctors if the problem doesn’t resolve.”
Right now, the ACS recommends colonoscopies or other screening tests start at age 50 for those with average risk and earlier screening for those with a family history of cancer. But this study shows young people often are diagnosed at a later stage because they aren’t getting screened, so some of these recommendations may need to be re-evaluated.
Colorectal cancer, which is malignancies in the colon or rectum, typically start as polyps on an inner wall of the large intestines. Though most polyps are benign, over time some can develop into cancer. The American Cancer Society estimates more than 95,000 new cases of colon cancer and almost 40,000 new cases of rectal cancer will be diagnosed in the United States in 2017. About 50,000 people will likely die of colorectal cancer this year.