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Rectal Cancer Facts

More than 40,000 people in the United States develop rectal cancer each year. When rectal cancer is found early, chances are good it can be treated successfully. Colon cancer and rectal cancer sometimes are grouped together and called colorectal cancer.

The rectum is a part of the digestive system, also called the gastrointestinal (GI) tract. The colon is the first 4 to 6 feet of the large intestine, also called the large bowel. The rectum is the last part of the large intestine, which ends in the anus.

Rectal cancer develops slowly and usually starts as polyps, which are overgrowths of tissue in the lining of the colon. Rectal cancer may develop within a polyp, but not all polyps contain cancer.

Rectal Cancer Types

More than 95% of colorectal cancers are adenocarcinomas. Approximately 90% of colorectal adenocarcinomas began as adenomas, which are a type of polyp that may become cancer.

Rectal Cancer Risk Factors

Anything that increases your chance of getting rectal cancer is a risk factor. Rectal cancer risk factors include:

  • Age: Rectal cancer is found most often in people over 50 years old.
  • Family history of colorectal cancer or polyps
  • Inherited disorders such as hereditary nonpolyposis colorectal cancer (HNPCC or Lynch) syndrome or familial adenomatous polyposis (FAP)
  • Race or ethnic background: African Americans and Jews of Eastern European descent (Ashkenazi Jews) are at higher risk.
  • Inflammatory bowel disease (Crohn’s disease or chronic ulcerative colitis)
  • Colorectal cancer or polyps
  • Obesity
  • Lack of exercise
  • Eating a lot of red meat, processed meats or meats cooked at very high heat
  • Diabetes Type 2
  • Cigarette smoking
  • Drinking too much alcohol

Not everyone with risk factors gets rectal cancer. However, if you have risk factors, it’s a good idea to discuss them with your doctor. If you are concerned about inherited family syndromes that may cause rectal cancer, we offer advanced genetic testing to let you know your risk.

Rectal Cancer Prevention

Certain lifestyle choices may lower your chances of getting rectal cancer. Try to:

  • Have regular screening tests
  • Stay at a healthy weight
  • Exercise regularly
  • Eat a healthy diet with lots of fruits and vegetables
  • Avoid cigarettes. 
  • Drink alcohol only in moderation

Some people have an elevated risk of developing rectal cancer. Review the rectal cancer screening guidelines to see if you need to be tested.

Some cases of rectal cancer can be passed down from one generation to the next. Genetic counseling may be right for you. Learn more about the risk to you and your family on our genetic testing page.

Clinical Trials

MD Anderson patients have access to clinical trials offering promising new treatments that cannot be found anywhere else.

Knowledge Center

Find the latest news and information about rectal cancer in our Knowledge Center, including blog posts, articles, videos, news releases and more.