Colorectal cancer (CRC) is the third most common cancer in both U.S. men and women. An estimated 50,000 U.S. adults will die this year from CRC, according to the American Cancer Society. Though the incidence of CRC is decreasing among those 50 and older, it is rising among adults under 50.
“Over the last two decades, we’ve seen an increase in younger adults at a rate of two percent per year,” says Dr. Paul Conarty, a colorectal surgeon with Parkview Physicians Group. He is also associate chief medical officer for Parkview Regional Medical Center. Based on current trends, by 2030 incidence rates for colon cancer among U.S. adults age 20-34 will increase by 90 percent and for rectal cancer by 124 percent; for adults ages 35-49, incidence of colon and rectal cancers will increase by nearly 28 percent and 46 percent, respectively, by 2030.
The alarming findings are from a study published in 2015 in the Journal of the American Medical Association (JAMA) Surgery. Similar data have been reported from other studies, spurring an urgent call for more research on causes of rising rates of CRC in the younger demographic and to perhaps rethink current screening recommendations.
Currently recommendations are initial colonoscopy screenings for average-risk adults begin at age 50. For the African-American adult with no personal or family history of polyps or CRC, screening should begin at 45.
Conarty says known factors that increase risk for this cancer include: obesity; inactivity; a diet high in red and processed meat; heavy alcohol use; cigarette smoking; personal history of inflammatory bowel disease; and a family history of colorectal cancer or polyps, especially in a first degree relative such as a parent or sibling.
“In people under 45, 20 percent to 30 percent (of diagnosed CRCs) have a hereditary link,” Conarty says, but only about 5 percent to 10 percent who develop CRC have inherited a gene mutation that leads to multiple family members developing the cancer. But these genetic forms of cancer are not the main cause for the steady rise in CRC among people under age 50. Researchers are looking at a variety of potential causes, including environmental such as pesticides and chemicals in foods. One study strongly suggests the obesity link, showing obese teens have double the risk for CRC by mid-life compared to normal weight teens.
When it comes to the family history link, it is not enough to know that dad had colon polyps or the Aunt Linda died from CRC.
“Other kinds of cancers, including breast, endometrial, bladder, ureter and some brain cancers, can be associated with increased risk of colorectal cancer,” Conarty says, so all adults need to know their family’s cancer history.
Still, these risk factors, whether they pertain to weight, lifestyle habits or family history, are not something physicians, for the most part, have addressed in relationship to CRC among younger adults.
Conarty says the medical community needs to be attentive to symptoms among all-age adults that could be indicative of CRC. The newly-formed Never Too Young Coalition is working to increase awareness of younger-onset CRC among physicians and patients. Likewise, patients should not hesitate to discuss recurrent gastrointestinal symptoms with their health-care provider. Younger-onset CRC tends to be discovered at more advanced stages than in older adults, resulting in high mortality rates in younger adults.
Screening via colonoscopy to detect polyps is key to prevention. Precancerous polyps can be found in their earliest stages and removed during the procedure. Yet for varying reasons, even among people 50 and older, only about 50 percent comply with screening recommendations.
For many, colorectal cancer is still a taboo topic. Conarty says, “They think it’s embarrassing.” They’ve heard stories about the dreaded colonoscopy prep so avoid scheduling the test. Lack of insurance or high deductibles are also barriers, and “fear of what they’ll find,” is why some avoid the exam, he said.
“When you look at the under 45 (population), the big message is that colorectal cancer is not unheard of,” Conarty says, advising people in their 20s, 30s and 40s with symptoms such as bleeding, pain, change in bowel habits or anemia to be evaluated.
No matter your age, head to your doctor if you have any of these symptoms that can be signs of colorectal cancer:
Source: American Cancer Society