What is colorectal cancer and is it preventable?

Actor James Van Der Beek died on 11 February, aged 48; he had been diagnosed in 2023 with colorectal cancer.

According to the World Health Organization, colorectal cancer is the third most common cancer and the second leading cause of cancer-related deaths worldwide. While rates are declining overall, cases among younger people are rising.

“This is a curable cancer if diagnosed early,” says Dr Deirdre Cohen, director of the gastrointestinal oncology program for the Mount Sinai health system and an associate professor of medicine. “It’s important to bring any symptoms to the attention of your physician.”

Here’s what you need to know about colorectal cancer.

What is colorectal cancer?

Colorectal cancer is an umbrella term for colon and rectal cancers, though these individual cancers are treated differently. The colon and rectum are parts of the large intestine, with the rectum positioned at the end of the colon.

In some cases, cancer appears in both locations, says Dr Derek Ebner, a gastroenterologist at Mayo Clinic in Rochester, Minnesota.

Is colorectal cancer preventable?

There’s no way to guarantee the prevention of colorectal cancer, and it can be a random event, says Cohen. But avoiding smoking and heavy alcohol use can reduce your risk.

She also emphasizes the importance of a healthy diet that includes plenty of fruits and vegetables, and avoiding processed meats like hot dogs and bacon.

According to the American Cancer Society, high consumption of red meat is also linked to a higher risk of colorectal cancer. A 2024 study published in the journal Cancer Epidemiology, Biomarkers & Prevention found that people with the highest level of red meat intake had a 30% increased risk for colorectal cancer. In the same study, individuals with the highest level of processed meat intake had a 40% increased risk.

In addition to a variety of brightly colored fruits and vegetables, Ebner recommends lean meats and high fiber to his patients. This often leads people to stick with the Mediterranean diet.

Exercise is another critical factor in risk reduction, says Cohen. It may also lower the risk of recurrence. A 2025 study published in the New England Journal of Medicine found that a three-year structured exercise program resulted in “significantly longer disease-free survival” and longer overall survival.

Colorectal cancer can be hereditary, and some genetic syndromes, like Lynch syndrome, are linked to it.

“If anyone has a first-degree relative, or a strong family history, they should see a genetic counselor for genetic testing and be considered for a colonoscopy at an earlier age,” says Cohen.

What’s the link between inflammation and colorectal cancer?

Chronic inflammation is a risk factor for various cancers, including colorectal cancer. The drivers of chronic inflammation vary. For example, inflammatory bowel disease and Crohn’s disease are both risk factors for the development of cancer due to the long-term inflammation of the colon.

Chronic inflammation related to alcohol use and ultra-processed foods can lead to an increased risk as well, explains Cohen.

The relationship between colorectal cancer and inflammation is still being explored, says Ebner. But it’s possible that inflammation generates free radicals, which are unstable molecules that cause DNA damage.

Is colorectal cancer becoming more common?

Overall, colorectal cancer is on a decline, associated with increased screening efforts. In recent years, there has been a push to spread awareness about the disease, says Ebner. Celebrity cases of colorectal cancer, like Van Der Beek and actor Chadwick Boseman, have also brought attention.

However, “a striking thing we’re seeing is the astronomical rise of colorectal cancer under the age of 50 and under the age of 40”, says Cohen.

For individuals under 50, rates of colorectal cancer have increased by about 3% annually since 2010, per the American Cancer Society. Colorectal cancer death rates have also increased by 1% annually in people younger than 50 since 2005.

It’s unclear why this rise is occurring, and potential drivers – like ultra-processed foods, sugary beverages and processed meats – are under investigation, says Cohen.

Higher antibiotic prescribing in childhood is linked to a higher risk of colorectal cancer in some studies; other research has found no evidence that antibiotic use in adulthood increases risk.

“The fact that it’s increasing at such a high incidence in younger people suggests there’s been some environmental change,” says Cohen.

What are the symptoms of colorectal cancer?

Colorectal cancer can be asymptomatic, so screening is important.

Symptoms can include blood in your stool or a change in stool pattern, such as frequent or months-long constipation or diarrhea. Sudden weight loss or abdominal pain can also indicate that you should speak with your care provider, says Cohen.

Patients may feel embarrassed to bring up these symptoms, says Ebner, but discussing these factors is normal.

“It’s important that your healthcare providers are made aware of anything so we can navigate if next steps should happen,” he says.

Who should be screened for colorectal cancer?

In the US, the US Preventive Services Task Force recommends screening beginning at age 45 for most individuals.

“People might be surprised to learn that roughly a third of individuals who are eligible for screening have not yet undergone any,” says Ebner.

Colorectal cancer can start as precancerous growths called polyps. These can form in the colon or rectum and turn into cancer over time. Finding and removing these polyps helps prevent cancer.

There are several ways to be screened, including a colonoscopy, stool-based screening tests and blood-based tests. Each test has different benefits and limitations, so it’s important to speak with your healthcare provider about which type is best for you.

The frequency of each test also differs: For example, a colonoscopy is performed every 10 years if results remain normal. A virtual colonoscopy, which is noninvasive and involves X-rays, may be conducted every five years.

“I tell my patients who are at average risk that the best test is the one that gets done,” says Ebner. “When people have an opportunity to choose the test that will work best for them, it improves the actual adherence to doing that test.”

Colonoscopy is the best strategy for those at high risk, he adds. It allows experts to identify and remove polyps simultaneously.

If you suspect something is awry, it’s important to advocate for yourself and pursue screening even if you’re not in the typical age group, says Cohen.

Is colorectal cancer treatable?

People with stage 1 colorectal cancer have a cure rate of more than 90%. The cure rate for stage 4 is closer to 15%.

Treatments can include surgery, radiotherapy, chemotherapy, targeted therapy and immunotherapy, depending on an individual’s case and disease stage.

Colorectal cancer is curable with early detection, explains Cohen. “Not every cancer has a screening tool that is effective, but in colorectal cancer, we do have that,” she says.