Colorectal cancer

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Hereditary colorectal syndromes

The following rare hereditary colorectal syndromes are precancerous conditions of the colon or rectum. They cause many polyps to develop in the colon and rectum. These syndromes are caused by a mutated, or changed, gene that can be passed from parents to children. They increase the risk of developing colorectal cancer.

Lynch syndrome is also called hereditary non-polyposis colorectal cancer (HNPCC). It is the most common type of hereditary colorectal syndrome. Most people with Lynch syndrome do not have an unusual number of polyps, which are small growths on a mucous membrane. If they do have polyps, they occur at an earlier age than in the general population and are more likely to become cancerous.

Familial adenomatous polyposis (FAP) causes hundreds to thousands of polyps to develop on the lining of the colon and rectum.

Peutz-Jeghers syndrome causes many hamartomas, or hamartomatous polyps, to grow in the digestive tract, including the colon and rectum.

Juvenile polyposis syndrome causes hamartomas to grow in the digestive tract, including the colon and rectum. These hamartomas usually form before age 20. Some people with this syndrome develop only a few hamartomas in the digestive tract. Other people can have over 100 hamartomas.

Risk factors

Your risk of having a hereditary colorectal syndrome depends on if family members have one of the mutated genes linked to the syndrome.


The symptoms of a hereditary colorectal syndrome depend on the type of syndrome and the number of polyps in the colon and rectum. You may not have any symptoms. When there are many polyps, they can cause:

  • changes in bowel habits
  • bleeding from the rectum
  • pain or discomfort in the abdomen
  • anemia
  • blockage in the intestine (called bowel obstruction)
  • part of the intestine slides into another nearby part of the intestine


If you have symptoms or your doctor thinks you might have a hereditary colorectal syndrome, you will be sent for tests. Tests used to diagnose a hereditary colorectal syndrome may include:

  • gastroscopy (a type of endoscopy that looks at the inside of the esophagus and stomach)
  • colonoscopy
  • biopsy
  • genetic testing

Find out more about these tests and procedures and genetic testing.

Treatment and follow-up

Treatments offered for hereditary colorectal syndromes depend on the number of polyps and if you have symptoms. Treatments may include:

  • removal of polyps (called polypectomy)
  • bowel resection with total colectomy or proctocolectomy

You will have regular screening with colonoscopy or sigmoidoscopy, as well as other tests. These tests are done to check the polyps and find cancer if it develops.


A non-cancerous (benign) tumour-like mass caused by an overgrowth of normal cells. 


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