Hereditary Colorectal Cancer Syndromes
CRC is the third most common cancer in US men and women. In approximately 20–30% of cases, CRCs are associated with a family history of colorectal polyps or cancer, but only 3–5% of cases are associated with an identifiable inherited CRC syndrome. Timely identification of at-risk individuals offers an opportunity to intervene before cancer develops. Content below is from a textbook reference chapter (Sabiston Ch52 - Colorectal Neoplasia & Colon Cancer Surgery), not primary literature; the chapter itself refers readers to the ASCRS Clinical Practice Guidelines for the Management of Inherited Polyposis Syndromes and for the Surgical Treatment of Patients with Lynch Syndrome for fuller detail.
Syndromes at a glance
| Syndrome | Gene(s) | Polyp type | Inheritance | CRC risk |
|---|---|---|---|---|
| Classical FAP | APC | Adenoma | AD | 100% |
| Severe FAP (>1000 adenomas) | APC | Adenoma | AD | 100% |
| Attenuated FAP (<100 adenomas) | APC | Adenoma | AD | 80% |
| MUTYH-associated polyposis (MAP) | MUTYH (biallelic) | Adenoma | AR | 80% |
| Juvenile polyposis syndrome (JPS) | SMAD4, BMPR1A | Hamartoma | AD | 40% |
| Peutz-Jeghers syndrome (PJS) | STK11 | Hamartoma | AD | 40% (39% specifically per the chapter) |
| Lynch syndrome | MLH1, MSH2, MSH6, PMS2, EpCAM | Nonpolyposis adenoma | AD | 60–80% (chapter gives 70% men / 40% women) |
See the dedicated pages for full detail:
- Familial Adenomatous Polyposis (FAP) — includes MUTYH-associated polyposis, which phenotypically mimics attenuated FAP.
- Lynch Syndrome
- Hamartomatous Polyposis Syndromes — Peutz-Jeghers syndrome and juvenile polyposis syndrome.
Open items / gaps
- No primary literature yet on any of these syndromes — all content is the textbook’s summary.
- Genetic counseling workflow (who orders testing, how results are communicated, family cascade testing logistics) is not covered by this chapter — a practical gap for a colorectal surgery practice.