Colon Cancer in Young Adults: An Alarming Trend

If you’re younger than 50, here’s something you need to know: Decades of data on colon (colorectal) cancer show a deadly trend that affects you.

Cancer of the colon and rectum now ranks as the leading cause of cancer-related death among men and people assigned male at birth (AMAB) aged 20 to 49 in the United States. For women and people assigned female at birth (AFAB), it’s now second behind only breast cancer, according to a 2024 report from the American Cancer Society.

That’s an alarming shift from the 1990s when colorectal cancer ranked fourth for both groups.

The change reflects a steady rise in colorectal cases in the under-50 crowd. In recent years, diagnoses have increased 1% to 2% annually among that demographic, while dropping for the overall U.S. population.

A similar pattern has been seen around the world, too, with documented increases in Canada, Australia, New Zealand and parts of Asia and Europe.

Let’s take a closer look at the trend with the help of colorectal surgeon David Liska, MD.

What’s causing the increase?

There’s no clear-cut answer to explain the growth in early-onset colon cancer. “More research is needed to better understand what is causing this rise in cases,” says Dr. Liska, director of the Center for Young-Onset Colorectal Cancer at Cleveland Clinic.

Many theories as to why focus on lifestyle factors and health conditions associated with colon cancer. The list includes:

• Rising obesity rates. Researchers note a distinct connection between body weight and colorectal cancer. Carrying an extra 20+ pounds (10 kilograms) brings about an 8% increase in colon cancer risk.
• Sedentary habits. Studies show that sitting for long periods while watching TV or working a desk job elevates colon cancer risk.
• Lack of physical activity. It’s estimated that 27% of adults around the world don’t meet recommended levels of physical activity. That’s a concern given that exercise seems to guard against colorectal cancer.
• Dietary choices. People tend to eat too much red meat, plus low-fiber, high-fat and processed food that adds to colon cancer risk. In addition, diets often don’t contain enough fruits and vegetables that can offer protective benefits.
• Smoking. While cigarette smoking is down overall, it remains higher among adults aged 25 to 44, according to the U.S. Centers for Disease Control and Prevention (CDC). Smoking has been established as a causal factor of colorectal cancer.
• Alcohol consumption. The National Cancer Institute reports that moderate to heavy alcohol consumption increases colon and rectum cancer risk.

But many early-onset cases don’t fit into any of the above categories. “We see plenty of younger people with colorectal cancer who are healthy and fit,” notes Dr. Liska. “So, it’s not just obesity or having a sedentary lifestyle. It’s a combination of factors.”

Some researchers — including a team at Cleveland Clinic — are looking into whether certain gut bacteria may be contributing to the growth of tumors in the intestines.

People at increased risk for colorectal cancer who usually need to be screened for the disease earlier and more frequently include those with:

• A family history of colorectal cancer.
• Inflammatory bowel diseases (like Crohn’s disease).
• Certain genetic syndromes (like Lynch syndrome and familial adenomatous polyposis, or FAP).

Symptoms of colon cancer in younger adults

Colorectal cancer comes with warning signs. Unfortunately, they’re frequently attributed to a less serious condition (such as hemorrhoids) or brushed off by those who think they’re too young for colorectal cancer.

Traditionally, colon cancer risk was tied to age with risk levels elevating after age 50.

“We often see younger patients with advanced cases of colorectal cancer who initially ignored their symptoms, which led to a delayed evaluation,” says Dr. Liska.

Early indicators of colorectal cancer could include:

• Blood on or in your stool (poop). (“There’s no such thing as ‘normal’ bleeding,” emphasizes Dr. Liska.)
• Changes in your bathroom habits, such as persistent constipation and/or diarrhea. Not feeling “done” after a bowel movement is another possible sign of a larger issue.
• Belly pain that’s intense and doesn’t just go away.
• Unexplained weight loss.

Now, does anyone really like talking to their healthcare provider about their poop patterns? Nope. It’s awkward, to say the least. But the conversation is important to start.

“Don’t assume that a change means nothing,” advises Dr. Liska. “Talk to your doctor so they can do an assessment. Colorectal cancer can be extremely treatable and curable, but early diagnosis is key.”

When to start colon cancer screenings

People increasingly getting colon cancer earlier in life brought changes to colorectal screening recommendations in 2021.

The U.S. Preventive Services Task Force lowered the age at which it recommends a screening from 50 to 45. If you have elevated risk factors, such as a family history of colon cancer, your healthcare provider may recommend starting screenings even earlier.

The adjustment was made with one primary goal in mind: Saving lives through early detection. “Knowing there is an issue is the first step to addressing it,” says Dr. Liska.

A colonoscopy is considered the “gold standard” for colon cancer screening. The procedure allows healthcare providers to find and remove any colon polyps that are cancerous or could become cancerous.

At-home stool tests are a less invasive option that can be effective at detecting colon cancer. But the tests are limited when it comes to finding precancerous polyps before they become a problem.

The use of screening programs is cited as the main reason why the number of colorectal cancer cases and deaths has been decreasing among people older than age 50.

How you can lower your colon cancer risk

The fact you’ve read this far is a good first step in protecting yourself against colorectal cancer. Understanding the risk is essential for staying a step ahead of the disease.

With that in mind, Dr. Liska offered these four tips.

1. Know your family history. Genetics can reveal a lot about your potential risk. “It’s extremely important to know if a close relative was ever treated for colorectal cancer or advanced colon polyps,” he says.
2. Get screened. Use available resources to get checked when the time comes. Colon cancer grows slowly, which gives you the opportunity to catch it before it becomes a life-threatening issue.
3. Talk to a healthcare provider. If something seems wrong downstairs, bring it up. “Take your health seriously, even if you’re in your 20s when you might feel that nothing can go wrong,” he encourages.
4. Live healthy. Exercise more. Sit less. Fill more of your plate with fruit and vegetables and cut back on red meat. Stop smoking. Limit your alcohol consumption.

“It is important to know what factors can increase the risk of developing colorectal cancer, what symptoms to be vigilant about and when to get screened,” stresses Dr. Liska. “There’s a lot you can do to protect yourself.”