Objective Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recognised as a morphologically and biologically heterogeneous group of neoplasms. Less is known about the epithelial subtypes of the precursor IPMN from which these lesions arise. The authors investigate the clinicopathological characteristics and the impact on survival of both the invasive component and its background IPMN. Design and patients The study cohort comprised 61 patients with invasive IPMN (study group) and 570 patients with pancreatic ductal adenocarcinoma (PDAC, control group) resected at a single institution. Multivariate analyses were performed using a stage-matched Cox proportional hazard model. Results The histology of invasive components of the IPMN cohort was tubular in 38 (62%), colloid in 16 (26%), and oncocytic in seven (12%). Compared with PDAC, invasive IPMNs were associated with a lower incidence of adverse pathological features and improved mortality by multivariate analysis (HR 0.58; 95% CI 0.39 to 0.86). In subtype analysis, this favourable outcome remained only for colloid and oncocytic carcinomas, while tubular adenocarcinoma was associated with worse overall survival, not significantly different from that of PDAC (HR 0.85; 95% CI 0.53 to 1.36). Colloid and oncocytic carcinomas arose only from intestinal-and oncocytic-type IPMNs, respectively, and were mostly of the main-duct type, whereas tubular adenocarcinomas primarily originated in the gastric background, which was often associated with branch-duct IPMN. Overall survival of patients with invasive adenocarcinomas arising from gastric-type IPMN was significantly worse than that of patients with non-gastric-type IPMN (p=0.016). Conclusions Tubular, colloid and oncocytic invasive IPMNs have varying prognosis, and arise from different epithelial subtypes. Colloid and oncocytic types have markedly improved biology, whereas the tubular type has a course that resembles PDAC. Analysis of these subtypes indicates that the background epithelium plays an equally, if not more, important role in defining the biology and prognosis of invasive IPMNs.

Background: Most cystic neoplasms of the pancreas (CNPs) are incidentally discovered. Their management continues to be debated and preoperative diagnosis is often inaccurate. Methods: Retrospective review of 330 patients with incidentally discovered CNPs. Preoperative and final histological diagnoses were correlated. Results: 41% (136/330) of patients were operated on at diagnosis. 50 patients underwent resection for a presumed branch-duct (Bd) intraductal papillary mucinous neoplasm (IPMN), which was confirmed in only 64% (32/50); of the remaining patients, 20% had main-duct involvement. Mucinous cystic neoplasm was the preoperative diagnosis in 30/136 patients, histologic examination was confirmatory in only 60% (18/30). Most lesions presumed to be main-duct or combined IPMNs or serous cystadenomas were confirmed as such after resection (15/16 and 11/12, respectively). Multifocality was not only associated with Bd-IPMN, and 5% of all cysts were non-neoplastic. Overall, in only 68% of cases did the preoperative and histological diagnoses match. Conclusions: In an experienced, high-volume center, preoperative diagnosis was incorrect in one-third of incidentally discovered CNPs who underwent resection. Of particular concern, 20% of presumed Bd-IPMN had a main-duct component. Conversely, 5% of resected cysts were not even neoplastic. Clearly, better diagnostic methods are needed to aid in formulating appropriate treatment strategies.

Purpose Evaluate conversion rate of patients with unresectable colorectal-liver metastasis to complete resection with hepatic-arterial infusion plus systemic chemotherapy including bevacizumab. Patients and Methods Forty-nine patients with unresectable CRLM were included in a single-institution phase II trial. Conversion to resection was the primary outcome. Secondary outcomes included overall (OS), progression-free survival (PFS), and response rates (RR). Multivariate and Landmark analyses were performed to evaluate survival differences between resected and non-resected patients. Results Median number of tumors was 14 and 65% were previously treated patients. A high biliary toxicity rate was found in the first 24 patients whose treatment included Bev. The remaining 25 patients were treated without Bev. Overall RR was 76% (4 complete responses). Twenty-three patients (47%) achieved conversion to resection at a median of 6 months from treatment initiation. Median OS and PFS for all patients was 38 (95% CI: 28–not reached) and 13 months (95% CI: 7–16). Bev administration did not impact outcome. Conversion was the only factor associated with prolonged OS and PFS in multivariate analysis. On landmark analysis, resected patients had longer OS compared to those who did not undergo resection (3-year OS: 80% vs. 26%). Currently 10 of 49 (20%) patients are NED at a median follow up of 39 months (32–65). Conclusion In patients with extensive unresectable CRLM, the majority of whom were previously treated, 47 % were able to undergo complete resection after combined HAI and systemic therapy. Conversion to resection is associated with prolonged survival.