Familial adenomatous polyposis

Bowel Cancer Australia

Rate this item
(0 votes)
Familial adenomatous polyposis (FAP) is a rare condition, responsible for about 1 in every 100 bowel cancers.

FAP is caused by a mutation on the adenomatous polyposis coli (APC) gene.
When mutated, the APC gene provides a selective advantage to early tumour cells, enabling them to proliferate.

FAP often starts in adolescence and is characterised by the presence of hundreds to thousands of adenomatous polyps (polyposis) in the large bowel.

An estimated 1-in-4 FAP cases occur in people with no genetic link.
However, FAP is usually inherited from a parent – carriers of FAP have a 50% chance of passing the condition on to their children.

Testing for a change of the APC gene currently detects 95% of mutations present.

When FAP is suspected, a person is referred by their GP to a Family Cancer Clinic for support and on-going management of the condition
Diagnosis is usually made following colonoscopy to confirm the presence of polyposis.

Screening usually commences from the age of 12-15, or from diagnosis, with annual flexible sigmoidoscopy or colonoscopy.

Without active management and screening on a regular basis, polyps often become cancerous by age 40.

Specialists, therefore recommend that people with FAP have surgery to have their colon removed by the age of 25 to prevent them getting bowel cancer.

This can be hard for a young person to cope with and they will need the specialist’s help and support of an experienced colorectal team to help make the right decision about their treatment.
If you have any questions about FAP or other genetic mutations please feel free to contact our Bowel Care Nurses on 1800 555 494 or send us an email.
Download our infographic to find out if bowel cancer is in your genes.
Support Bowel Cancer Australia
Bowel Cancer Australia Social Media