The natural history of untreated duodenal and ampullary adenomas in patients with familial adenomatous polyposis followed in an endoscopic surveillance program

Background: Endoscopic surveillance is recommended for patients with famili al adenomatous polyposis (FAP) because of the high prevalence of duodenal a denomas and the risk of periampullary cancer. The aim of this study was to assess the natural history of untreated duodenal and ampullary adenomas in FAP patients during surveillance. Methods: One hundred fourteen FAP patients who had 2 or more surveillance e xaminations were followed for a mean of 51 months (range, 10 to 151 months) . Results: Duodenal polyps progressed in size in 26% (25 of 95), number in 32 % (34 of 106), and histology in 11% (5 of 45) of patients. Morphology and h istology of the main duodenal papilla progressed in 14% (15 of 110) and 11% (12 of 105) of patients, respectively. The histologic progression was mild except for one patient who developed a periampullary cancer. Conclusions: A minority of FAP patients had progression of endoscopic featu res and histology of duodenal polyps or the main duodenal papilla when foll owed over 4 years. An endoscopic surveillance interval of at least 3 years may be appropriate for the majority of untreated patients with FAP. Factors that stratify patients as being at the highest risk of periampullary cance r and thus requiring more intensive surveillance are yet to be determined.