LAUSR

Simple Summary Pancreatic cancer has a poor prognosis, even in patients that can be surgically treated with curative intent. An interesting subgroup of resected pancreatic cancers are those associated with pancreatic cystic neoplasms (PCN), since overall survival might differ from pancreatic cancer not associated with PCN. Although several single-center studies published conflicting data on this topic, nationwide studies are lacking. In this nationwide, registry-based study, we aimed to compare the overall survival between patients with PCN-associated pancreatic cancers to those with pancreatic cancer not associated with PCN. We found that 12% of resected pancreatic cancers patients were PCN-associated. Overall survival was better in patients with PCN-associated pancreatic cancer as compared to those not associated with PCN. Future prospective studies should focus on the impact of these findings, such as the impact of (neo)adjuvant treatment regimens in this specific patient group. Abstract Background: Outcome after resection of pancreatic ductal adenocarcinoma associated with pancreatic cystic neoplasms (PCN-PDAC) might differ from PDAC not associated with PCN. This nationwide, registry-based study aimed to compare the overall survival (OS) in these patients. Methods: Data from consecutive patients after pancreatic resection for PDAC between 2013 and 2018 were matched with the corresponding pathology reports. Primary outcome was OS for PCN-PDAC and PDAC including 1-year and 5-year OS. Cox regression analysis was used to correct for prognostic factors (e.g., pT-stage, pN-stage, and vascular invasion). Results: In total, 1994 patients underwent resection for PDAC including 233 (12%) with PCN-PDAC. Median estimated OS was better in patients with PCN-PDAC (34.5 months [95%CI 25.6 to 43.5]) as compared to PDAC not associated with PCN (18.2 months [95%CI 17.3 to 19.2]; hazard ratio 0.53 [95%CI 0.44–0.63]; p < 0.001). The difference in OS remained after correction for prognostic factors (adjusted hazard ratio 1.58 [95%CI 1.32−1.90]; p < 0.001). Conclusions: This nationwide registry-based study showed that 12% of resected PDAC were PCN-associated. Patients with PCN-PDAC had better OS as compared to PDAC not associated with PCN.