Familial adenomatous polyposis (FAP) is an inherited predisposition to numerous colorectal adenomas and a high risk of colorectal cancer without appropriate prevention. An adenoma is a type of polyp with the potential to become cancerous; finding a polyp is not the same as diagnosing cancer. Classic and attenuated forms differ in their usual polyp burden and timing. [1]
In this guide: When should polyposis prompt a genetics discussion? · How do FAP, APC and other syndromes differ? · Prepare for a hereditary gastrointestinal cancer visit · Why is prevention more than one colonoscopy? · How can a confirmed result help relatives? · How should we judge a prevention study? · Continue with related guides and tools
When should polyposis prompt a genetics discussion?
Multiple adenomatous polyps, a relevant family history or a known familial APC pathogenic variant can prompt assessment. The specialist considers the cumulative polyp history and other findings, not just the number removed at one procedure. APC-associated conditions can also involve sites outside the colon. [2]
Collect the colonoscopy and pathology reports together. The procedure report describes what was seen and removed; pathology describes the tissue examined. A useful personal timeline records the date, approximate burden, locations, pathology wording and the clinician’s recommendation. If earlier records are missing, mark that gap rather than assuming the most recent procedure represents the whole history.
How do FAP, APC and other syndromes differ?
FAP and attenuated FAP are associated with pathogenic variants in APC. Other hereditary colorectal conditions include MUTYH-associated polyposis and Lynch syndrome, which involve different genes and biological pathways. Similar presentations do not mean that testing, inheritance or management is identical. [3]
APC encodes a tumor-suppressor protein involved in controlling cell growth through pathways including Wnt signaling. The companion APC gene guide explains how a molecular result should be connected to the polyp history and specimen type. A gene name on a tumor report does not automatically describe inherited family risk. [4]
Prepare for a hereditary gastrointestinal cancer visit
- Bring the records: collect colonoscopy, pathology, surgery and genetic reports.
- Describe the family: distinguish confirmed polyposis, cancer diagnoses and uncertain recollections.
- Clarify the testing question: diagnosis in an affected person or targeted testing for a known family finding?
- Read the result precisely: keep classification, date, specimen and test limitations together.
- Separate pending decisions: identify which depend on more information and which require action now.
- Agree responsibility: know who will arrange surveillance, referrals and result discussions.
For a family without a confirmed molecular explanation, ask how the existing clinical findings affect care while testing continues. A negative test is not permission to ignore a documented polyp burden. Our test limitations guide explains why the scope of an assay matters.
Why is prevention more than one colonoscopy?
Management can involve repeated endoscopic assessment and polyp removal, with colorectal surgery when indicated. The choice and timing depend on factors such as polyp burden, pathology and the feasibility of surveillance. Follow-up can remain necessary after surgery, including assessment of retained bowel and the upper gastrointestinal tract. [2]
Use the specialist’s written schedule rather than an interval copied from a general article. Ask which anatomical areas require follow-up and why. If surgery is being discussed, request an explanation of the proposed procedure, remaining surveillance needs and practical effects on daily life. Record questions about recovery, fertility, work or education so they are addressed before a decision.
- Which findings are driving the current recommendation?
- What would lead to a change in the plan?
- Who tracks the next examination and follows up a missed appointment?
- What symptoms should trigger an earlier contact?
- Which concerns outside the colon are relevant to this person?
How can a confirmed result help relatives?
APC-associated polyposis is usually autosomal dominant: a person with a constitutional pathogenic variant can transmit it to a child. A family may nevertheless have no previously recognized diagnosis. Genetic counseling connects the actual finding to family testing and age-appropriate assessment. [1]
Start with the original report and a clinician-prepared explanation where available. The cascade testing guide helps organize invitations for assessment without treating untested relatives as negative. Keep family information private and give relatives a clear route to their own clinical advice.
How should we judge a prevention study?
Separate fewer polyps from fewer cancers, less surgery or improved quality of life. Each is a different outcome. Record the initial polyp burden, prior surgery, concurrent surveillance and follow-up duration. A short study with a favorable polyp-count result cannot, by itself, establish every long-term prevention benefit.
For a journal-club comparison, create columns for intervention, comparator, measured outcome, adverse events and unanswered question. Note how missing follow-up was handled. Use absolute and relative risk to check whether a headline describes an actual event difference or a proportional change in a surrogate measure.
Continue with related guides and tools
Read the APC gene guide, Lynch syndrome guide and tumor versus germline testing. The variant research assistant, care finder and literature tools support non-identifying research and professional directories. They do not replace a surveillance plan from a hereditary gastrointestinal cancer team.
Educational information, not an individual diagnosis or treatment plan. The current specialist-review status appears above. Illustrations are original educational examples, not patient records.