Screening for Duodenal Adenoma in Familial Adenomatous Polyposis
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, 2
Rationale for Screening Timing
The timing of duodenal screening is based on several key considerations:
- European Society for Medical Oncology (ESMO) guidelines specifically recommend that screening for extracolonic manifestations, including gastroduodenal polyposis, should start when colorectal polyposis is diagnosed or at the age of 25-30 years, whichever comes first 1
- This recommendation is consistent across multiple guidelines, including the American Society of Clinical Oncology (ASCO) endorsement of the ESMO guidelines 1
- The risk of duodenal cancer increases with age, with most cases occurring after age 50, but adenomas can develop much earlier 3
Surveillance Protocol
Once screening begins, the surveillance intervals should be guided by the Spigelman classification, which assesses duodenal polyposis severity:
| Spigelman Stage | Polyp Burden | Recommended Interval |
|---|---|---|
| Stage I or II (mild) | Few, small polyps | Every 3-5 years |
| Stage III (moderate) | Multiple, larger polyps | Every 1-3 years |
| Stage IV (severe) | Numerous, large polyps | Every 6 months to 1 year |
Risk Stratification
The risk of progression to duodenal cancer varies significantly based on Spigelman stage:
- Stage IV disease carries a 36% risk of developing duodenal cancer 3
- Stage III disease has approximately 2% risk of progression to cancer 3
- Stage II disease also has approximately 2% risk of progression to cancer 3
Special Considerations
Early Onset Disease
Recent evidence suggests that children with FAP may develop clinically relevant duodenal lesions earlier than previously recognized:
- A study of 69 children with FAP found that 52% had duodenal adenomas with low-grade dysplasia at a mean age of 13.5 years 4
- Meta-analysis of 5 series demonstrated duodenal adenoma detection rate of 39% in pediatric FAP patients 4
Endoscopic Technique
Proper endoscopic technique is crucial for adequate assessment:
- Gastroduodenal endoscopy should use both front and side-view scopes to properly visualize the duodenum and ampulla 1
- Special attention should be paid to the periampullary region, as 50% of duodenal carcinomas in FAP patients occur in this location 5
Management of Findings
- Patients with duodenal adenomas ≥10 mm and ampullary adenomas of any size should be referred to expert centers for endoscopic therapy 5
- Endoscopic management may include endoscopic mucosal resection and endoscopic ampullectomy 5
- Patients with Spigelman stage IV disease or adenomas with persistent severe dysplasia should be considered for surgical intervention before invasive cancer develops 6
Pitfalls to Avoid
Delayed screening: Starting screening too late may miss early adenomas that could progress to advanced disease.
Inadequate visualization: Failure to use both forward and side-viewing endoscopes may miss lesions, particularly in the periampullary region.
Underestimating severity: Comprehensive endoscopic assessment is essential to avoid underestimating the severity of duodenal polyposis, especially in high-risk patients.
Inappropriate intervals: Not adjusting surveillance intervals based on Spigelman stage can lead to missed opportunities for early intervention.
Overlooking pediatric risk: While guidelines recommend starting at age 25-30, clinicians should be aware that significant duodenal adenomas can occur in pediatric FAP patients.