Endoscopic papillectomy for ampullary lesions in patients with familial adenomatous polyposis compared to sporadic lesions in a propensity-score matched cohort

Background: Familial-adenomatous-polyposis (FAP) is a rare inherited cancer predisposition syndrome. The treatment for FAP-related ampullary lesions (AL) is challenging and the role of endoscopic papillectomy (EP) is not elucidated yet. Data of FAP associated AL are limited and showed, at least in part, inconclusive results. We retrospectively analyzed the outcomes of EP in matched cohorts of FAP-related and sporadic ampullary lesions (SAL). Methods: The ESAP study included 1422 EPs. A propensity-score matching (nearest-neighbor-method) including age, gender, comorbidity, histologic subtype and size was performed. Main outcomes were complete resection (R0), technical success, complications and recurrence. Results: Propensity-score-based matching identified 202 patients (101 FAP, 101 SAL) with comparable baseline characteristics. FAP-patients were mainly asymptomatic (79.2% [95%CI 71.2-87.3] vs. 46.5% [95%CI 36.6-56.4]), p<0.001). The initial R0-rate was significantly lower in FAP-patients (63.4% [95%CI 53.8-72.9] vs. 83.2% [95%CI 75.8-90.6], p=0.001). After repeated (mean: 1.30 per patient) interventions, R0 was comparable (FAP 93.1% [95%CI 88.0-98.1] vs. SAL 97.0% [95%CI 93.7-100], p=0.194). The overall complication rate was 28.7%. Pancreatitis and bleeding were most common adverse events in both groups. Severe complications were very rare (3.5%). Twenty-one patients in the FAP-group (20.8% [95%CI 12.7-28.8]) and sixteen patients in the SAL-group (15.8% [95%CI 8.6-23.1], p=0.363) had a reccurence . Recurrences occurred later in FAP-patients (25 [95%CI 18.3-31.7] vs. 2 [95%CI CI 0.06-3.9] months). Conclusions: EP is safe and effective in FAP-related ampullary lesions Criteria for endoscopic resection of AL can be extended to FAP-patients. FAP-patients have a life-time risk to relapse even after complete resection and require long-time-surveillance.