Branch-duct intraductal papillary mucinous neoplasm (BD-IPMN): a retrospective study on neoplastic risk after 5 years surveillance

Abstract

Objectives: Long term surveillance of branch-duct intraductal papillary mucinous neoplasms (BD-IPMN) remains controversial, particularly regarding cysts follow up > 5 years. The primary endpoint of this study was to assess the risk of malignant transformation of presumed BD-IPMN during follow-up and identify clinical and morphological predictors of malignancy. Methods: We performed a retrospective analysis of data from all patients with a presumed BD-IPMN diagnosis at the CIUSSS de l’Estrie CHUS, from 2004-2018. Results: The final database included 380 patients with presumed BD-IPMN with a median follow up of 43,9 months (IQR 28,6-73,3 months). Mean age at diagnosis was 65,5 years [27-90], 159 patients (42,8%) were male and 17 patients (4,5%) underwent resection of their lesion during their surveillance period. In our cohort, 132 patients (34,7%) had a follow-up > 5 years. Overall risk of malignancy was 2.1% [0.9%-4.1%]. During follow-up, neoplastic transformation was observed in 2/132 patients (1,5%) surveilled > 5 years. Malignancy was significantly associated with cyst growth > 2,5 mm/year (57,1% vs 5,8% p < 0,001) dilated MPD (71,4% vs 4,9% p<0,001), solid component (71,4% vs 1,3% p<0,001), positive cytology (37,5% vs 0,5% p<0,001), development of high-risk stigmatas (87,5% vs 1,9% p <0,001) or worrisome features (87,5% vs 23,9% p<0,001) during follow up and symptoms of jaundice (25% vs 0,5% p=0,002) and abdominal pain (50% vs 9,4% p=0,005). Conclusion: While overall malignancy risk remains low in presumed BD-IPMN, continuous surveillance should be pursued after 5 years in surgically fit individuals, particularly in patients who develop our identified risk factors.