Adjuvant chemotherapy after surgery for intraductal papillary mucinous neoplasms of the pancreas: promising observational data call for controlled studies

Abstract

Introduction: Little is known about the role of adjuvant treatment after surgery for malignant Intraductal Papillary Mucinous Neoplasms (IPMNs).The aim of this study is to assess the potential role of adjuvant chemotherapy in terms of improvement of survival. Methods: Retrospective evaluation of all patients with resected IPMNs with high grade dysplasia (HGD) or invasive carcinoma (iCa) at the Department of General and Pancreatic Surgery - The Pancreas Institute, University of Verona, with univariate and multivariate analysis for determinants of disease specific survival (DSS) were performed.Kaplan-Maier curves were used to compare patients. Results: From 467 resected IPMNs, we identified 195 patients: 110 (56%) with iCa and 85 (44%) with HGD.As expected, none of the patients with HGD received adjuvant therapy, while 22.7% of patients with IPMN-iCa did.The most used chemotherapy regimen was Gemcitabine (72%).Overall, the median DSS for IPMN-iCa was 208 months.The median DSS of IPMN treated with adjuvant therapy was not reached, while it was 94 months for surgery alone (p< 0.01).Predictors of DSS were adjuvant therapy (HR=0.42; CI=0.26-0.67; p< 0.01), tubular invasive component (HR=5.79; CI=2.69-12.45; p< 0.01) and pancreatobiliary epithelial type (HR=2.85; CI=1.3-7.87; p=0.03). At multivariate analysis, adjuvant therapy resulted an independent predictor of DSS (HR=0.45; CI=0.20-0.98; p< 0.04).Stratifying for pathological features,adjuvant therapy was independently associated with DSS only in case of tubular invasive component. Conclusions: Adjuvant therapy for IPMNs with iCa is associated with improved DSS compared with surgery alone, especially in case of tubular invasive component. Future controlled trials are needed to improve the level of evidence.