Progression of Periampullary Adenomas in Familial Adenomatous Polyposis
Abstracts
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Background: The main cause of death following colectomy in patients with familial adenomatous polyposis (FAP) is upper gastrointestinal malignancy, therefore, periodic endoscopic surveillance is recommended. However, there is no consensus on the frequency or management of periampullary polyps. The specific aim of this study was to understand the natural history of duodenal polyps in FAP in order to devise a more evidence-based protocol for surveillance in FAP. Methods: 115 FAP patients were followed prospectively over a 10-year period, with upper GI endoscopies performed by a single surgeon, based on a protocol developed in 1990. Polyps were classified according to their size into stages 1 to 5. Statistical analysis included one-way ANOVA for the age comparisons between stage groups, and Kaplan-Meier analysis for the lifetime risks of having a particular stage. Results: There were 54 males (47%) and 61 females (53%). The average age at colectomy was 29.9 (range 9-62) and the average age at first side-viewing upper endoscopy was 39.1 (range 16-69). There was a significant difference between the mean age at first endoscopy for stage 1 (37.3 years) and stage 4 (54.0 years) patients (p = 0.02), as well as for stage 2 (37.3) and stage 4 patients (p = 0.03). Of the 115 patients, 87 (76%) had 2 or more endoscopies and were followed for an average of 6.6 years (range 1-15). Of the patients with at least 2 endoscopies, 33 (38%) had a change in stage, in an average time of 3.94 years (range 0-13) at an average age of 40.9 years (range 22-74). There were no significant differences when comparing average time to first stage change across groups categorized by stage at first endoscopy. The stage at first endoscopy did not correlate with the degree of dysplasia in the periampullary polyps. The progression of the periampullary adenomas in patient that had 2 or more upper GI endoscopies was very slow. Close to 90% of patients had periampullary polyps by the age of 75. The risk of having stage 3 or higher polyposis increased sharply after the age of 40. Conclusions: The stage of duodenal polyposis increases with age in FAP. The average time for change in stage was 3.9 years at an average age of 41. These values are not influenced by the initial stage. We cannot comment on the progression of adenoma to carcinoma, since none of the patients developed carcinoma during the study period. The degree of dysplasia did not correlate with initial stage. The risk of having a higher staged polyp is exponentially increased in FAP patients after the age of 40. |
