Rise in colorectal cancer among adults younger than 50 leads to new screening guidelines
Lowering the age of testing could result in 11,000 deaths averted over 5 years.
New guidelines are calling for adults to begin screening for colorectal cancer at age 45 instead of 50, a recommendation that makes an additional 21 million Americans eligible for colonoscopy or other screening methods.
The U.S. Preventive Services Task Force, the preeminent scientific body responsible for national health recommendations, recently issued a draft version of the new guidelines, which are expected to be finalized in the coming months. The move was in response to an increase in colorectal cancer among younger adults.
“This is a major departure from what they have recommended in the past for colorectal cancer screening, which was to start at age 50,” says UCLA Health gastroenterologist and gastroenterology quality improvement director Folasade P. May, MD, PhD, MPhil. “Everyone needs to know that once these recommendations are formalized, if you’re 45 years old, you’re already due — don’t wait five years.”
Colorectal cancer is the third-leading cause of cancer-related deaths in the U.S., says Carol Mangione, MD, MSPH, chief of general internal medicine at UCLA Health and vice-chair of the U.S. Preventive Services Task Force. “Our hope is that with this new recommendation, dropping the screening age down to 45, that it will save lives,” she says.
Data show that 29,000 cases of colorectal cancer could be identified and 11,000 deaths averted over five years with the change in screening guidelines, Dr. May says.
Though the majority of colorectal cancer is diagnosed in people older than 50, cases of early onset of the disease have been on the rise for several decades, Dr. May says. About 11% of colon cancers and 18% of rectal cancers appear in people younger than 50. At the same time, colorectal cancer among people older than 65 has declined.
Scientists continue to study what’s causing the rise in colorectal cancer among younger adults, an increase of about 2% a year. While obesity and diabetes may play a role, colorectal cancer also can present in perfectly healthy people, Dr. May says.
"We think it's probably a multifactorial effect of not only things like family history, obesity and diabetes, but also lifestyle factors like diet, physical activity and other exposures," she says. "Things like stress and antibiotic use over a lifetime, maybe even the microbiome and the bacteria that live in our gut -- it might be all of these things together that are driving this.
“This is no longer a disease of older Americans,” she says. “This is a disease that’s affecting younger people and that is the crux of what has shaped these new recommendations.”
The new guidelines advise people age 45 and older to undergo colonoscopy or other methods of colorectal cancer screening. This doesn’t mean that those older than 50 are off the hook, however: The recommendations still call for people age 50 to 75 to be regularly screened for the disease; currently, only about 65% of Americans in that age group follow through with screenings.
Colonoscopy isn’t the only option, though it is the most comprehensive screening, being it allows for both the visualization and removal of potentially cancerous polyps. During the procedure, a physician inserts a flexible camera scope into the colon, which allows for the identification of polyps, which Dr. May describes as “little pimples” that can become cancerous.
Colonoscopy requires a day of preparation— during which the patient consumes a clear, liquid diet and a laxative drink to clear the bowels — along with a day off work and sedation during the procedure. Provided the patient isn’t at high risk and the results are normal, a colonoscopy is generally repeated every 10 years.
“Some Americans can’t take a weekday off. Some Americans don’t like the idea of doing the prep. Some Americans are terrified of hospitals or any invasive procedure,” says Dr. May. “So, luckily for colorectal cancer we have other methods of screening. I think focusing on multiple modalities is the only way we’re going to get the additional 21 million screened.”
Perhaps the easiest screening method is the fecal immunochemical test, or FIT, which can be performed at home. Primary care doctors can typically provide a take-home kit during a clinic visit. The FIT includes a small tool, which the patient uses to remove a tiny stool sample from the toilet, and a vial to contain the sample. The sample is sent to a lab, where it is analyzed for microscopic traces of blood, which could indicate a polyp or cancer.
About 5% to 10% of FIT find traces of blood, Dr. May says, and those patients are asked to follow up with a colonoscopy.
The FIT must be performed annually to be effective, but if results are normal, a patient can avoid a colonoscopy. “We have the data now that show that FIT performs very well so long as patients do it every year,” Dr. May says.
However, FIT isn’t an option for those with a family history of colorectal cancer or those with predisposing conditions such as ulcerative colitis, Crohn’s disease or prior radiation to the abdomen. Colonoscopy is recommended for these patients.
While the new recommendations reduce the age at which colorectal cancer screenings should start, some people still need to be checked before age 45. Those with a family history of colorectal cancer should begin screening at age 40, Dr. May says. And if a family member was diagnosed at a particularly young age, screening should begin even earlier than 40.
“For example, if your mother was diagnosed at 35, you should begin screening 10 years earlier than the age at which she was diagnosed — so age 25,” Dr. May says. “That’s how aggressive we are.”
Knowing your family history of the disease is critical, she says. It’s also important to recognize signs and symptoms of colorectal cancer and bring them to your doctor’s attention. These include red or black stool, changes in the shape of the stool, new abdominal pain that’s severe, new constipation or diarrhea, changes in appetite and significant unintentional weight loss. When these symptoms occur, colonoscopy is recommended, even if the individual has not reached screening age.
Black Americans are at higher risk of being diagnosed with and dying from colorectal cancer, Dr. May says. Her research team at UCLA focuses specifically on increasing screening for this group.
Colorectal cancer is highly treatable and survivable when detected early, according to the American Cancer Society, which is why regular screening is so important.
When the new guidelines are finalized, health insurance companies will be required to cover colorectal cancer screenings for everyone 45 and older.