Treatment strategy for pancreatic IPMNs: prognostic impact of conservative surgery

Purpose: The aim of this study is to analyze the prognostic impact of conservative surgery for pancreatic IPMNs. Materials and methods: We retrospectively analyzed surgical and post-operative data of all pancreatic resections for IPMN performed at our center in a ten-years period. Patients were divided in three different groups based on preoperative indications and post-operative histopathological findings: 1) patients undergone pancreatic resection according to the current guidelines and with histopathological proven IPMN with low to high grade dysplasia (IPMN group); 2) patients with same features at preoperative imaging but with histopathological accidental findings of carcinoma (IPMN-PDAC group); 3) patients with PDAC at preoperative imaging with histopathological accidental discovery of collateral IPMN (PDAC-IPMN group). The Kaplan-Meier method was used to compare the OS and the DFS of the three groups. Results: From November 2007 to December 2017, 108 patients underwent pancreatic resections for IPMN. 25 patients were included in the IPMN group, 20 in the IPMN-PDAC group and 63 in the PDAC-IPMN group. The OS and DFS were 117.6 and 141.6 months respectively, in the IPMN group, 37.8 and 36.6 months respectively, in the IPMN-PDAC group and 47.9 and 60.8 months respectively, in the PDAC-IPMN group. We found a better prognosis for the IPMN group (p<0.05), while no significant differences between the other two groups. Considering the operation, there were not differences between partial (55% of patients) or total pancreatectomy in terms of OS and DFS, although there was a higher rate of postoperative surgical complications in patients treated with conservative surgery (p<0.05), but without affecting the length of hospital stay and the 30-day mortality. Only 22.4% of patients developed diabetes after conservative surgery. None of patients treated with conservative surgery needed a completion of pancreatectomy due to the progression of IPMN lesions with worrisome features or PDAC in the remnant pancreas during the follow-up. Conclusions: The prognosis of patients with IPMN depends on the presence of malignancy progression into invasive cancer, even if at an early stage, and not on the extension of surgery. A timely, conservative surgery may be considered an appropriate choice, thus avoiding serious long-term metabolic consequences.