Guideline sources The following summarized guidelines for the evaluation and management of familial adenomatous polyposis (FAP) are prepared by our editorial team based on guidelines from the European Society of Gastrointestinal Endoscopy (ESGE 2023), the American Society for Gastrointestinal Endoscopy (ASGE 2020), and the American College of Gastroenterology (ACG 2015). 1 2 3 Guidelines 1. Screening and diagnosis Indications for screening: perform screening sigmoidoscopy or colonoscopy in pediatric patients with definite or suspected FAP at ages 10-12 years. B Show 3 more 2. Diagnostic investigations Genetic testing: obtain genetic counseling and testing in patients with clinical polyposis defined as 10 adenomas found on a single endoscopy and 20 adenomas during their https://web.pathway.md/diseases/recSheLhax8rSQTnp 1/4 6/29/23, 4:02 AM Familial adenomatous polyposis Pathway lifetime. B Show 2 more 3. Diagnostic procedures Upper gastrointestinal endoscopy: perform careful examination of the ampulla and periampullary region using a duodenoscope or cap-assisted gastroscope given the predilection for cancer in this area. B Biopsy: perform biopsy sampling of the ampulla to assess for villous histology or dysplasia only in patients with an identifiable mucosal abnormality, while avoiding the pancreatic orifice because of the risk for pancreatitis. B 4. Medical management Chemoprevention: offer chemopreventive agents within the confines of a tertiary hereditary cancer center and/or as part of clinical trials. B 5. Therapeutic procedures Endoscopic resection: Perform endoscopic resection of: gastric and duodenal polyps > 1 cm, given the risk of developing dysplasia all antral polyps, given the predominance of gastric adenomas in this location. B 6. Surgical interventions Indications for colectomy: Perform immediate colectomy in patients with FAP, attenuated FAP or MUTYH-associated polyposis in the presence of documented or suspected cancer or significant symptoms. B Consider performing colectomy in patients with FAP, attenuated FAP or MUTYH-associated polyposis in the presence of multiple adenomas > 6 mm, a significant increase in adenoma number, and inability to adequately survey the colon because of multiple diminutive polyps. B 7. Follow-up and surveillance Surveillance endoscopy, colon: As per ASGE 2020 guidelines: Perform follow-up colonoscopy in patients with rectosigmoid polyps if sigmoidoscopy was the initial screening test. B Perform surveillance colonoscopy at 1-2 year intervals in patients with FAP B , attenuated FAP or MUTYH-associated polyposis. B As per ACG 2015 guidelines: https://web.pathway.md/diseases/recSheLhax8rSQTnp 2/4 6/29/23, 4:02 AM Familial adenomatous polyposis Pathway Obtain screening for colorectal cancer by annual colonoscopy or flexible sigmoidoscopy beginning at puberty in patients at risk for or affected with the classic adenomatous polyposis syndromes. B Perform surveillance colonoscopy in families with attenuated FAP or MUTYH-associated polyposis. B Surveillance endoscopy (small bowels): obtain surveillance of the proximal small bowel in patients with FAP using conventional forward-viewing and side-viewing endoscopes. B Show 2 more Post-operative surveillance: As per ASGE 2020 guidelines: Perform pouch endoscopy or ileoscopy at 1-2 year intervals in patients with ileal pouch anal anastomosis or ileostomy. B Perform sigmoidoscopy at 6-months to 1-year intervals indefinitely in patients with ileorectal anastomosis. B As per ACG 2015 guidelines, obtain postsurgical surveillance by yearly endoscopy of rectum or ileal pouch, and examination of an ileostomy every 2 years. B Surveillance for extracolonic malignancies: As per ASGE 2020 guidelines: Perform upper gastrointestinal surveillance endoscopy based on the interval advised for the most severely affected organ, whether stomach or duodenum. B Perform random sampling biopsy and targeted biopsy sampling of any suspicious lesions during surveillance examination to assess for dysplasia and accurate duodenal Spigelman stage. Recognize that baseline Spigelman score 7 is associated with development of duodenal high-grade dysplasia. B As per ACG 2015 guidelines, perform upper gastrointestinal endoscopy including duodenoscopy starting at age 25-30 years to screen for gastric and proximal small bowel tumors. Obtain repeated surveillance every 6 months to 4 years depending on Spigelman stage of duodenal polyposis: Situation Guidance 4 years 0 2-3 years I 1-3 years II 6-12 months III Surgical evaluation. B IV Show 3 more Clinical findings https://web.pathway.md/diseases/recSheLhax8rSQTnp 3/4 6/29/23, 4:02 AM Familial adenomatous polyposis Pathway Symptoms Past medical history Abdominal pain Colorectal cancer Bloating Colorectal polyps Constipation Hepatoblastoma Diarrhea Pancreatic cancer Fatigue Thyroid cancer Hematochezia Mucus in stools Pain with bowel movements Rectal bleeding Weight loss Endoscopic findings References 1. Sapna Syngal, Randall E Brand, James M Church et al. ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes. Am J Gastroenterol. 2015 Feb;110 2 223 62; quiz 263. Open 2. Julie Yang, Suryakanth R Gurudu, Cathryn Koptiuch et al. American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in familial adenomatous polyposis syndromes. Gastrointest Endosc. 2020 May;91 5 963 982.e2. Open 3. Marco Pennazio, Emanuele Rondonotti, Edward J Despott et al. Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy ESGE Guideline Update 2022. Endoscopy. 2023 Jan;55 1 58 95. Open 4. Monique E van Leerdam, Victorine H Roos, Jeanin E van Hooft et al. Endoscopic management of polyposis syndromes: European Society of Gastrointestinal Endoscopy ESGE Guideline. Endoscopy. 2019 Sep;51 9 877 895. Open https://web.pathway.md/diseases/recSheLhax8rSQTnp 4/4