Long-term Outcomes following Resection of Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasm (A-IPMN) versus Pancreatic Ductal Adenocarcinoma (PDAC)

Objective: The aim of the present study was to compare long-term post-resection oncological outcomes between A-IPMN and PDAC. Summary Background Data: Knowledge of long term oncological outcomes (e.g recurrence and survival data) comparing between adenocarcinoma arising from intraductal papillary mucinous neoplasms (A-IPMN) and pancreatic ductal adenocarcinoma (PDAC) is scarce. Methods: Patients undergoing pancreatic resection (2010-2020) for A-IPMN were identified retrospectively from 18 academic pancreatic centres and compared with PDAC patients from the same time-period. Propensity-score matching (PSM) was performed and survival and recurrence were compared between A-IPMN and PDAC. Results: 459 A-IPMN patients (median age,70; M:F,250:209) were compared with 476 PDAC patients (median age,69; M:F,262:214). A-IPMN patients had lower T-stage, lymphovascular invasion (51.4%vs. 75.6%), perineural invasion (55.8%vs. 71.2%), lymph node positivity (47.3vs. 72.3%) and R1 resection (38.6%vs. 56.3%) compared to PDAC( P <0.001). The median survival and time-to-recurrence for A-IPMN versus PDAC were 39.0 versus19.5months ( P <0.001) and 33.1 versus 14.8months ( P <0.001), respectively (median follow-up,78 vs.73 months). Ten-year overall survival for A-IPMN was 34.6%(27/78) and PDAC was 9%(6/67). A-IPMN had higher rates of peritoneal (23.0 vs. 9.1%, P <0.001) and lung recurrence (27.8% vs. 15.6%, P <0.001) but lower rates of locoregional recurrence (39.7% vs. 57.8%; P <0.001). Matched analysis demonstrated inferior overall survival ( P =0.005), inferior disease-free survival ( P =0.003) and higher locoregional recurrence ( P <0.001) in PDAC compared to A-IPMN but no significant difference in systemic recurrence rates ( P =0.695). Conclusions: PDACs have inferior survival and higher recurrence rates compared to A-IPMN in matched cohorts. Locoregional recurrence is higher in PDAC but systemic recurrence rates are comparable and constituted by their own distinctive site-specific recurrence patterns.