Colorectal Cancer Risk Factors

How do you get colorectal cancer? What puts you at a higher 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?

Anyone can get colorectal cancer (CRC). The lifetime risk for colorectal cancer is 5%, or one in 20. 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.

Colorectal Cancer Risk 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. The older your age, the higher your risk of colon cancer. According to the National Cancer Institute, the average age of a colorectal cancer patient is 68.

Although your risk of developing colorectal cancer increases with age, anyone at any age can get CRC. Rates of colorectal cancer patients under age 50, a phenomenon referred to as early-age onset colorectal cancer, 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. All average-risk adults should talk to their doctors about colorectal cancer screening at age 45.

The following factors are linked to a higher risk of colorectal 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 Colorectal Cancer

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

  • Family history of colorectal cancer
  • Family history of colon polyps
  • Personal history of colon polyps, colon cancer, rectal cancer, ovarian cancer, endometrial cancer, or breast cancer
  • Personal diagnosis of type 2 diabetes
  • Previous radiation therapy directed at the abdomen

Race and Ethnicity Plays a Role

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.

Advanced/High-Risk for Colorectal Cancer

Carrying an advanced or high risk for colorectal cancer means you need to be aggressively undergoing screening and working alongside a physician who is monitoring you. You will be at an advanced risk 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 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. Although your risk is above average, colorectal cancer is still preventable.

Reducing Your Risk of Getting Colorectal Cancer

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 which risk level you find yourself in, 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!