AARP Eye Center
Colorectal cancer rates are declining among adults 65 and older, but researchers are picking up on a few concerning trends when it comes to the third-leading cause of cancer deaths in the U.S.
A new report from the American Cancer Society finds that the proportion of individuals diagnosed with advanced-stage colorectal cancer is on the rise, increasing from 52 percent in the mid-2000s to 60 percent in 2019. What’s more, diagnoses of colorectal cancer in people under 55 has doubled in the last few decades, from 11 percent in 1995 to 20 percent in 2019.

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“We know rates are increasing in young people, but it’s alarming to see how rapidly the whole patient population is shifting younger, despite shrinking numbers in the overall population,” Rebecca Siegel, senior scientific director of surveillance research at the American Cancer Society, said in a statement. “The trend toward more advanced disease in people of all ages is also surprising and should motivate everyone 45 and older to get screened.”
In fact, the U.S. Preventive Services Task Force updated its guidelines in 2021 to say that individuals should get an initial screening for colorectal cancer at age 45, instead of waiting until they’re 50. One reason screening is so important is because colorectal cancer, which is expected to affect 153,020 people in the U.S. in 2023, often doesn’t cause symptoms in the early stages, says Scott Kopetz, M.D., a professor in the Department of Gastrointestinal Medical Oncology, Division of Cancer Medicine, at the University of Texas MD Anderson Cancer Center in Houston. And catching the cancer in its earlier stages can be lifesaving.
“One take-home message is that screening shouldn’t be based on symptoms,” Kopetz stresses. “When you do have symptoms, colorectal cancer tends to be more advanced. That’s why it’s so important to follow screening guidelines.”
That said, the following red flags indicate you should be checked out immediately, even if you’ve recently had cancer screening such as a colonoscopy.
- A change in bowel habits (think diarrhea, constipation or narrowing of your stool) that lasts for more than a few days.
- An urge to have a bowel movement that’s not relieved by having one.
- Rectal bleeding. “Any bleeding you see, even if it’s just one time, should not be ignored,” says Daniel Labow, M.D., executive vice chair of the Department of Surgery at the Mount Sinai Health System in New York City.
- Dark brown or black stool (which can indicate blood).
- Cramping or belly pain.
- Weakness and fatigue.
- Unexplained weight loss. If you have colorectal cancer, your body releases certain hormones into your bloodstream that can lead to weight loss, even if you continue to eat normally, Labow says.
- Unexplained anemia. “It could be from losing blood from someplace like your rectum,” Labow says.
Here’s our comprehensive guide to everything you need to know about the disease.
Colorectal cancer defined
Colorectal cancer starts in either your colon or your rectum, both of which are parts of the large intestine. Most of these cancers start out as polyps, or growths on the inner lining of your colon or rectum. “Some types of polyps can turn cancerous, but not all polyps become cancer,” says David Liska, M.D., a colorectal surgeon at the Cleveland Clinic.
If cancer forms in a polyp, it grows into the wall of the colon or rectum. It starts in the inner layers (known as the mucosa), then grows outward through all the other layers. Eventually, it can grow into blood or lymph vessels, where it can travel to lymph nodes and finally spread to distant parts of your body.