Risk Factors for Colon Cancer

The following risk factors increase your chance of developing colon cancer — but they are all things you can control:

  • a diet high in red, processed, or heavily cooked meats
  • a lack of exercise
  • obesity, particularly excess fat around the waist
  • smoking (studies show that smokers are 30 to 40 percent more likely to die of colorectal cancer)
  • drinking too much alcohol

Some risk factors can’t be controlled. These include:

Most colon cancers occur after age 50 (unless there is a family history of the disease or a hereditary cause).

Colon polyps are abnormal growths on the inside surface of the large intestine. They can be found anywhere in the large intestine and can range in size from tiny to very large. Some polyps, known as precancerous polyps, can develop into colon and rectal cancer over time. During colonoscopy, we are able to identify polyps and remove them to decrease the risk of cancer.

Polyps are very common. We don’t know exactly why some people get polyps and others don’t, but there are some known environmental and genetic factors. Smoking, drinking alcohol, being obese, consuming a lot of red meat or having a diet high in fat and low in fiber have all been shown to increase the risk of developing polyps. A personal or family history of colon polyps (especially if they are large or numerous) or colon or rectal cancer also can increase the likelihood of developing polyps.

There are some inherited disorders that dramatically increase your risk of developing colon cancer. These include Lynch syndrome and familial adenomatous polyposis. Learn more about these and other inherited conditions that affect your risk for colon cancer as well as our genetic testing services.

If you’ve had colon cancer before, you’re at an increased risk of developing it again.

Inflammatory bowel diseases such as ulcerative colitis and Crohn’s colitis increase your risk of colon cancer.

You have an increased risk for colon cancer if:

  • a close family member, such as a parent or sibling, had colon cancer before age 50;
  • several blood relatives have had colon cancer; or
  • there is a family pattern of certain other cancers, including endometrial, ovarian, gastric, urinary tract, brain, and pancreatic cancers.

People who regularly use aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDS) may have a lower risk of colon cancer and polyps. Aspirin may also help prevent polyp growth in people who were previously treated for early-stage colon cancer or who previously had colon polyps removed.

However, NSAIDs can have serious side effects and should be taken only under your doctor’s direction. Aspirin can cause stomach bleeding in some people, and drugs such as celecoxib may increase the risk of heart attack and stroke.

Using hormone-replacement therapy (HRT) consisting of estrogen and progesterone after menopause may reduce a woman’s risk of colon cancer. However, HRT can potentially cause other health problems. Talk to your doctor to learn more about the potential benefits and risks associated with HRT.