Risk Factors for Rectal Cancer

The following risk factors increase your chance of developing rectal 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 rectal cancers occur after age 50 (unless there is a family history of the disease or a hereditary cause).

If you have precancerous polyps (abnormal growths on the inside surface of the rectum), you’re more likely to develop rectal cancer. This is especially true if they’re large or you have a lot of them. 

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

If you’ve had rectal 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 rectal cancer.

You have an increased risk for rectal cancer if:

  • a close family member, such as a parent or sibling, had rectal cancer before age 50;
  • several blood relatives have had rectal 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 rectal cancer and polyps. Aspirin may also help prevent polyp growth in people who were previously treated for early-stage colorectal cancer or who previously had 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 rectal 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.