Colorectal Cancer Risk Factors

What are the colon cancer risk factors? How do you get colorectal cancer? Who is at high risk? How do you lower your chances of getting it? First, it’s important to realize there are some circumstances that you can control and others you can’t.

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Who’s at Risk for Colorectal Cancer?

What are the colon cancer risk factors? First, it's important to remember anyone can get colorectal cancer. The lifetime risk for colorectal cancer is 5%, or one in 20. This means, statistically speaking, out of 20 people, 1 person will get colorectal cancer.

Colorectal cancer affects both men and women, as well as people of all ages, races, and ethnicities. It is one of the only truly preventable cancers thanks to screening.

Risk of Colorectal Cancer by Age

Over 90% of people diagnosed with colorectal cancer are over age 50. As we age, we are more likely to grow colon polyps which may undergo gene changes that turn normal tissue into cancer. This is why age is one of the top colon cancer risk factors. The older your age, the higher your risk of colon cancer.

According to the National Cancer Institute, cancers of the colon and rectum are most frequently diagnosed in people aged 65-74, with the median age of diagnosis being 66.

Although your risk of developing colorectal cancer increases with age, anyone at any age can get CRC. Rates of colorectal cancer in young adults, or patients under age 50, is a phenomenon referred to as early-age onset colorectal cancer, and cases are on the rise.

Fight Colorectal Cancer is funding research and working alongside experts to discover why this is happening.

Average-Risk for Colorectal Cancer

Most people you walk past every day are considered “average-risk” adults and equally face colon cancer risk factors. All average-risk adults should talk to their doctors about colorectal cancer screening at age 45.

Here are the most common risk factors for colon cancer and rectal cancer:

  • Inactivity (little physical activity and exercise)
  • Overweight and obese 
  • Little fruit, vegetable, and fiber consumption
  • Smoking
  • Heavy alcohol use (more than one drink/day for women and two drinks/day for men)
  • A diet high in red meat (beef, pork, lamb), processed meats, and fats 
  • Meat preparation including frying, grilling, broiling, or other methods of cooking at very high temperatures

Increased Risk for Colon Cancer

In addition to the risk factors for colorectal cancer that apply to average-risk adults, these situations will increase your colorectal cancer risk:

Race and Ethnicity Plays a Role in Colon Cancer Risk

Of all racial groups in the U.S., African Americans have the highest incidence and mortality rates, although the cause of this is not currently known. Worldwide, Jews of Eastern European descent (Ashkenazi Jews) have the highest risk of colorectal cancer. Doctors may suggest earlier screening if your race and ethnicity present an increased risk.

Get colorectal cancer statistics about racial groups.

High Risk for Colorectal Cancer

Carrying an advanced or high risk for colorectal cancer means you need to be aggressively checked for colorectal cancer. A colonoscopy would most likely be recommended and considered a diagnostic procedure, rather than a "screening colonoscopy" or at-home colon cancer test.

If you're high risk for colorectal cancer, you need to stay in close contact with a physician who can monitor you. You will be at an advanced risk for colorectal cancer if:

  • You’ve tested positive for a genetic syndrome like Lynch syndrome or FAP
  • A first-degree or second-degree relative has a genetic syndrome
  • You’ve been diagnosed with an inflammatory bowel disorder (IBD) such as ulcerative colitis or Crohn’s Disease

If your family has a known genetic syndrome, screening may need to be performed earlier. Talk to your doctor about when to begin.

Even if you didn’t inherit it, genetic syndromes in the family may increase your chance of getting colorectal cancer.

Are You at Risk for Colorectal Cancer?

Learn more about genetic risk factors in our Genetics Mini Mag.

Risk of Colon Cancer Recurrence

If you’ve been diagnosed with colorectal cancer once, you’re at an increased risk of developing a second cancer or facing a recurrence. If your cancer tested positive for a hereditary colorectal cancer syndrome, you are at high risk.

It’s imperative as a survivor, you work with your team and follow an aggressive follow-up screening plan as part of your survivorship care planning. Although your risk for colon cancer is above average, colorectal cancer is still preventable.

Reducing Your Colon Cancer Risk Factors

Getting screened for colorectal cancer is the most effective, and most important, way to prevent it and reduce your risk. However, there are lifestyle changes that can reduce your risk of polyps and colorectal cancer.

Convincing Evidence

  • Don't smoke, and if you do, stop smoking
  • Increase your physical activity (get at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity each week)
  • Maintain a healthy body weight
  • Avoid overall body fat, especially fat around your waist
  • Reduce how much red meat and processed meats you eat
  • Use alcohol in moderation

Probable Evidence

  • Eat more foods that contain dietary fiber
  • Include garlic in your diet
  • Drink more milk if you can tolerate it
  • Add foods with calcium

More Information

No matter your colon cancer risks, it’s important to remember that colorectal cancer is preventable! In addition to knowing the risk factors, make sure you know the signs and symptoms and when you should get screened for colon cancer.