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. 2024 May 9;111(5):znae070. doi: 10.1093/bjs/znae070

Table 1.

Short version: statements pertaining to the lower gastrointestinal manifestations

Statements Level of evidence and agreement
Surveillance
 LGI.1A: Surveillance should begin at 12 years of age in asymptomatic patients with a germline PV in the APC gene (for FAP disease), or in asymptomatic patients with FDRs affected by classical FAP (if a genetic test is not available or if no PV is detected in the affected relative). LE: low
Agreement: 83%
(SA 49%; A 34%; N 7%; D 10%)
 LGI.1B: In symptomatic patients with germline PV in the APC gene (for FAP disease), or patients with FDRs affected by classical FAP if a genetic test is not available or if no PV is detected) colonoscopy should start at any age and as soon as possible. LE: low
Agreement: 90%
(SA 56%; A 34%; N 3%; D 7%)
 LGI.2A: Surveillance can start later but no later than 18–20 years of age in asymptomatic patients with a germline PV in the APC gene for attenuated FAP disease and an attenuated proband/family phenotype. Alternatively, surveillance should also begin in asymptomatic patients with first–degree relatives affected by attenuated FAP, if a genetic test is not available or if no known pathogenic mutations are detected. LE: low
Agreement: 69%
(SA 31%; A 38%; N 17%; D 4%; SD 10%)
 LGI.2B: Colonoscopy should start at any age and as soon as possible in symptomatic patients with a germline PV in the APC gene for a-FAP disease or in patients with FDRs affected by a-FAP (if a genetic test is not available or if no known pathogenic mutations are detected). LE: low
Agreement: 90%
(SA 55%; A 35%; N 7%; D 3%)
 LGI.3: The optimal modality for colorectal surveillance in classical FAP is high-definition white-light colonoscopy. Flexible sigmoidoscopy can be considered as an initial option, according to patient preference. If adenomas are identified high-definition white-light colonoscopy should be performed. LE: low
Agreement: 100%
(SA 55%; A 45%)
 LGI.4: The optimal modality for colorectal surveillance in a-FAP is high-definition white-light colonoscopy. LE: low
Agreement: 92%
(SA 71%; A 21%; N 8%)
 LGI.5A: Endoscopic surveillance of the colon should be adapted according to phenotype, genotype–phenotype and the severity of the disease. LE: low
Agreement: 90%
(SA 40%; A 50%; N 7%; D 3%)
 LGI.5B: Repeat endoscopy should be performed within 1 year or less if at least one of the following criteria is present:

  • APC germline PV of codon 1309 associated with a severe phenotype.

  • Presence of ≥100 adenomas at colonoscopy.

  • Presence of large polyps at colonoscopy (≥10 mm).

  • Symptoms.

  • Rapid progression in terms of polyp size.

 LE: low
Agreement: 87%
(SA 57%; A 30%; N 3%; D 10%)
 LG.5C: Repeat endoscopy may be performed at 2 years when the phenotype shows all of the following criteria:

  • Presence of 0–20 adenomas.

  • Presence of small adenomas at colonoscopy (1–2 mm)

  • Absence of symptoms.

 LE: low
Agreement: 70%
(SA 20%; A 50%; N 20%; D 10%)
 LGI.6A: White-light high-definition colonoscopy is sufficient for surveillance colonoscopy in FAP. LE: low
Agreement: 89%
(SA 56%; A 33%; N 7%; D 4%)
 LGI.6B: There are insufficient data to recommend the use of advanced imaging technology. LE: low
Agreement: 93%
(SA 55%; A 38%; N 7%)
 LGI.6C: White-light endoscopy is sufficient in most cases; virtual or dye-based chromoendoscopy could have advantages in discriminating between the clinical diagnosis of FAP versus a-FAP. LE: low
Agreement: 73%
(SA 23%; A 50%; N 23%; D 4%)
Surgery
 LGI.7: Absolute indications for immediate colorectal surgery in FAP are:

  • Certain or suspected cancer.

  • Severe symptoms from polyposis.

  • Severe disease (≥1000 polyps at colonoscopy).

  • Unfavourable histological features (such as HGIEN, villous adenoma, etc.).

 Indications for planned surgery are:

  • Polyps >10 mm in diameter.

  • Favourable histological features.

  • Substantial increase in polyp number between examinations.

  • Sparse disease (100–1000 polyps).

 LE: low
Agreement: 93%
(SA 57%; A 36%; N 3.5%; D 3.5%)
 LGI.8A: IPAA may be offered to patients with either:

  • 20 or more rectal adenomas.

  • Approximately 500 or more colonic adenomas.

  • APC mutation at codon 1250–1450.

 IRA may be offered to:

  • Patients with 5 or fewer rectal adenomas and less than 500 colonic adenomas.

 LE: low
Agreement: 86%
(SA 29%; A 57%; N 14%)
 LG.8B: Patient preference about surgical choice should be considered. LE: low
Agreement: 100%
(SA 44%; A 56%)
 LGI.9: There is no conclusive evidence indicating a clear advantage or disadvantage in performing dissection with mesocolic/mesorectal excision. LE: low
Agreement: 96%
(SA 31%; A 65%; SD 4%)
 LGI.10: Routine diverting ileostomy is not mandatory when total proctocolectomy with IPAA is performed. LE: low
Agreement: 80%
(SA 55%; A 25%; N 10%; D 5%; SD 5%)
 LGI.11: When the rectum can be preserved, an ileo-sigmoid anastomosis could be considered to diminish the risk of anastomotic leak and improve functional outcome. LE: low
Agreement: 95%
(SA 24%; A 71%; SD 5%)
Post-surgical management
 LGI.12A: The optimal modality for surveillance after an IRA is endoscopy. The surveillance interval should not exceed 2 years, starting from the colectomy, and should be individualized based on phenotype. LE: low
Agreement: 93%
(SA 57%; A 36%; D 3.5%; SD 3.5%)
 LGI.12B: All polyps >5 mm should be removed (endoscopically or with transanal excision). LE: low
Agreement: 86%
(SA 41%; A 45%; N 7%; D 7%)
 LGI.12C: Secondary proctectomy should be considered when polyposis is no longer conservatively manageable or in the presence of two or more polyps with HGD. LE: low
Agreement: 100%
(SA 52%; A 48%)
 LGI.13A: Endoscopic surveillance of an ileo-anal pouch should start 12 months after colectomy. LE: low
Agreement: 88%
(A 88%; N 12%)
 LGI.13B: Endoscopic surveillance of an ileo-anal pouch should be performed annually. LE: low
Agreement: 81%
(SA 29%; A 52%; D 14%; SD 5%)
 LGI.14A: Pouch adenomas may be managed endoscopically. LE: low
Agreement: 100%
(SA 57%; A 43%)
 LGI.14B: In the presence of HGD in/of complete polyp resection, the pouch should be surveilled within 6 months. LE: low
Agreement: 100%
(SA 50%; A 50%)
 LGI.14C In the presence of two or more polyps with HGD, surgery may be considered. LE: low
Agreement 100%
(SA 52%; A 48%)
 LGI.15: In the case of pouch carcinoma, pouchectomy/dismantling of the pouch is indicated. LE: Expert opinion
Agreement 100%
(SA 58%; A 42%)
 LGI.16: Expanding endoscopy to the more proximal small bowel should be performed during pouchoscopy in FAP patients after total proctocolectomy with IPAA. LE: low
Agreement 100%
(SA 48%; A 52%)

A, agree; a-FAP, attenuated familial adenomatous polyposis; D, disagree; FAP, familial adenomatous polyposis; FDR, first-degree relatives; HGD, high-grade dysplasia; HGIEN, high-grade intraepithelial neoplasia; IPAA, ileal pouch anal anastomosis; IRA, ileorectal anastomosis; LE, level of evidence; N, neutral; PV, pathogenic variant; SA, strongly agree; SD, strongly disagree.