Familial Adenomatous Polyposis

When do adenomas develop?

Adenomas are not present at birth. Adenomas generally begin around puberty, that is, from the age of 10-12. This is very different from the more common history of a 50- or 60-year-old person who may develop one or two adenomas. Most people with FAP are diagnosed in their teens or early 20's. It is estimated that only 1% of all bowel cancer is due to FAP.

Two things may happen to adenomas over time: they increase in size and number. Adenomas form initially in the rectum and lower colon. Some people have hundreds or thousands of adenomas while others, particularly adolescents, may have fewer adenomas. One hundred polyps is the average number of polyps in a person with FAP but this depends on how old he or she is. This can be an important clue to treatment. Without early diagnosis and treatment, the risk of colon cancer is 100%. FAP is a pre-cancerous disease because 1) adenomas will change to cancer in approximately 5 to 10 years and 2) prevention of colon cancer is possible.


Adenomas in a segment of colon.

Introduction and Definition

Where do adenomas grow?

When do adenomas develop?

How will I know if I have FAP?

How is FAP diagnosed?

What is the treatment for FAP?

Where else can adenomas develop?

Who is at risk for FAP?

zur Stoma-Seite


Development - Familial Gastrointestinal Cancer Registry - Mount Sinai Hospital, Toronto

Familial Adenomatous Polyposis

When do adenomas develop?

Adenomas are not present at birth. Adenomas generally begin around puberty, that is, from the age of 10-12. This is very different from the more common history of a 50- or 60-year-old person who may develop one or two adenomas. Most people with FAP are diagnosed in their teens or early 20's. It is estimated that only 1% of all bowel cancer is due to FAP.

Two things may happen to adenomas over time: they increase in size and number. Adenomas form initially in the rectum and lower colon. Some people have hundreds or thousands of adenomas while others, particularly adolescents, may have fewer adenomas. One hundred polyps is the average number of polyps in a person with FAP but this depends on how old he or she is. This can be an important clue to treatment. Without early diagnosis and treatment, the risk of colon cancer is 100%. FAP is a pre-cancerous disease because 1) adenomas will change to cancer in approximately 5 to 10 years and 2) prevention of colon cancer is possible.


Adenomas in a segment of colon.

Introduction and Definition

Where do adenomas grow?

When do adenomas develop?

How will I know if I have FAP?

How is FAP diagnosed?

What is the treatment for FAP?

Where else can adenomas develop?

Who is at risk for FAP?

zur Stoma-Seite