A rise in rectal cancer rates is driving an increase in colorectal cancer diagnoses in people younger than 65, according to a report published Monday from the American Cancer Society.
Colorectal cancer rates in people under 65 are surging, with nearly half (45%) of new diagnoses occurring in this age group, up from 27% in 1995. At the same time, colorectal cancer rates are falling in people 65 and older.
Rectal cancers on their own, however, are rising in all adults, and now account for nearly one-third of all colorectal cancer diagnoses, up from 27% in the mid-2000s, the report found.
Between 2018 and 2022, rectal cancer diagnoses rose by 1% each year in all age groups.
Researchers don’t understand why this particular type of cancer is increasing in prevalence.
“We didn’t have an epidemic of young people with colon or rectal cancer up until recently,” said Dr. Arif Kamal, chief patient officer for the American Cancer Society. “It’s really a phenomenon in the last five years or so that we’ve started to see this.”
The report found that colorectal cancer rates since the late 1990s:
- Increased by 3% each year for people ages 20 to 49
- Increased by 0.4% each year for adults ages 50 to 64
- Decreased by 2.5% each year for adults 65 and older.
The shift toward younger adults with colorectal cancer is prompting doctors to urge earlier education about the disease that, for generations, was considered something that only occurred in older age.
“We know young patients are presenting with signs and symptoms, and that there’s about a 4- to 6-month gap between symptom presentation and diagnosis, which is alarming,” said Andreana Holowatyj, an assistant professor of hematology and oncology at Vanderbilt University Medical Center. “How do we educate Gen Zers, millennials and future generations?” Holowatyj was not involved with the new research.
What are the symptoms of rectal cancer?
Colorectal cancers include cancers of the large intestine, the bulk of which is the colon. The rectum is found at the very end of the large intestine, just before the anus.
Kamal said that tumors in the rectum cause symptoms that tend to be “a little more dramatic” compared to tumors in the colon.
Colon cancer symptoms can be vague, including fatigue, abdominal pain, bloating and unexplained weight loss. Rectal cancers are often accompanied by bright red blood on toilet paper or in the toilet bowl and a real urgency to use the bathroom even after a bowel movement.
“While we don’t know the drivers” of the increase in rectal cancer, Kamal said, “it does emphasize the importance of knowing your body and reporting symptoms to your doctor early.”
When should people start screening for colorectal cancer?
Until recently, colorectal cancer screening was only recommended for people 50 and older. In 2021, the U.S. Preventive Services Task Force lowered the age for screening to 45.
Some people are at higher risk for colorectal cancer and should be considered for earlier screening, according to current guidelines. Those include people who have a family history of the disease or who have had precancerous polyps or inflammatory bowel disease.
According to the new report, however, just more than a third of people ages 45 to 49 are getting screened. About three-quarters of colorectal cancers in people younger than 50 are diagnosed after the disease had progressed to an advanced stage.
Now that colorectal cancer diagnoses are trending younger, it’s possible that the recommended age for screening will need to be revisited, Kamal said.
“There will be decisions to be made within the next couple years, for sure,” he said.
Caitlin Murphy, a cancer epidemiologist at the University of Chicago, said there’s growing interest in “fast-tracking” people under age 45 who develop symptoms that could signal colorectal cancer.
“Patients tend to get stuck in referral loops, where they get referred to this person who then refers them to this person, and just goes on and on and on for months,” said Murphy, who was not involved with the new report. “We want to make sure that people get timely treatment, so the cancer doesn’t continue to advance while they’re waiting for it to be diagnosed.”
How to lower colorectal cancer risk
Colorectal cancer is the nation’s No. 1 cause of cancer death in people under age 50. The new report estimates that 158,850 new colorectal cancers will be diagnosed in 2026. Approximately 55,230 patients will die from the disease, with nearly a third of those deaths in people under age 65.
Researchers link more than half of colorectal cancers to controllable risk factors: smoking, high alcohol consumption, lack of exercise and excess body weight.
Making dietary changes, including boosting fiber, vegetables, fruit and whole grain intake and cutting back on processed meats, can also lower the risk, according to the American Cancer Society.
