Outcome after pancreatectomy for neuroendocrine neoplams according to the WHO 2017 grading system: A retrospective multicentric analysis of 138 consecutive patients.

The aim of this study was to evaluate the new World Health Organization (WHO) 2017 grading system and the others clinicopathological factors in pancreatic neuroendocrine tumor (panNET) operated patients.Histological staging was based on the WHO 2017 grading system. Outcome after surgery and predictors of overall survival (OS) and disease free survival (DFS) were evaluated.A total of 138 patients underwent surgical resection with a severe morbidity and mortality rates of 14.5% and 0.7% respectively. Five years OS differed according to WHO 2017: 95% among 58 patients with NETG1, 82% in 68 patients with NETG2, 35% in 7 patients with NETG3 and 0% in 5 patients with NECG3 (P<0.0001). Independent predictors of worse OS were age>60 y.o (P=0.014), synchronous metastasis (P=0.005) and WHO 2017 with significant differences between NETG1 versus NETG2 (P=0.005), NETG3 (P<0.001) and NECG3 (P<0.001). Independent predictors of worse DFS were symptomatic NET (P=0.038), pN+ status (P=0.027) and WHO 2017 with significant differences between NETG1 versus NETG3 (P=0.014) and NECG3 (P=0.009).The WHO 2017 grading system is a useful tool for patient prognosis after panNET resection and the tailoring of therapeutic strategy. Surgery could provide good results in NETG3 patients.