Screening for Duodenal Adenoma in Patients with FAP
Screening for duodenal adenomas in patients with Familial Adenomatous Polyposis (FAP) should begin at age 25-30 years or when colorectal polyposis is diagnosed, whichever comes first. 1
Rationale for Screening
- Duodenal adenomas develop in up to 90% of FAP patients, with a cumulative lifetime risk of 5-10% for developing duodenal or periampullary adenocarcinoma 2
- Duodenal cancer is one of the leading causes of death in FAP patients who have undergone prophylactic colectomy 3, 2
- Early detection through appropriate screening can help identify precancerous lesions before they progress to malignancy 1
Screening Protocol
Initial Screening
- Upper GI endoscopic surveillance should begin at age 25-30 years or when colorectal polyposis is diagnosed, whichever comes first 1
- Both front and side-viewing endoscopes should be used, with special attention to the papillary area 1
- A minimum of 30 random biopsies is recommended for thorough assessment 1
Follow-up Intervals Based on Spigelman Classification
The frequency of subsequent screenings should be guided by the Spigelman classification, which assesses the severity of duodenal polyposis 1:
- Spigelman Stage 0 (0 points): Repeat endoscopy every 5 years 1
- Spigelman Stage I (1-4 points): Repeat endoscopy every 5 years 1
- Spigelman Stage II (5-6 points): Repeat endoscopy every 3 years 1
- Spigelman Stage III (7-8 points): Repeat endoscopy annually and consider endoscopic therapy 1
- Spigelman Stage IV (9-12 points): Repeat endoscopy every 6-12 months and consider endoscopic or surgical therapy 1
Risk Stratification
- Patients with Spigelman stage IV disease have a significantly higher risk (36%) of developing duodenal cancer compared to those with stage II or III disease (2%) 3
- The median age at diagnosis of stage 3 disease (adenomas 2.1-10 mm) is 41 years, and stage 4 disease (adenomas >10 mm) is 45 years 4
- The risk of developing stage 4 disease is 34.3% at 15 years after initial endoscopy 4
Management Considerations
- Duodenal adenomas are usually managed by endoscopic polypectomy, although surgery (duodenectomy or duodenal-pancreatectomy) may be necessary in advanced cases 1
- Local excision of duodenal adenomas is associated with a high risk of local recurrence (approximately 58%) 5, 6
- Pancreaticoduodenectomy should be considered for patients with Spigelman stage IV disease, as this group has a high risk of developing adenocarcinoma if left untreated 3, 2
Special Considerations
- Patients with MUTYH-associated polyposis (MAP) develop duodenal adenomas less frequently and at a later age than FAP patients, but should follow the same surveillance recommendations starting at age 25-30 years 5, 1
- For patients with attenuated FAP (AFAP), the same duodenal surveillance protocol is recommended as for classical FAP 1
- Aggressive endoscopic and surgical intervention, especially for large polyps and high-grade dysplasia, appears effective in preventing cancer deaths in FAP 4