Macrovascular venous invasion of pancreatic neuroendocrine tumours: impact on surgical outcomes and survival

BackgroundThis study evaluates the impact of macrovascular venous invasion (MVI) on surgical and survival outcomes of pancreatic neuroendocrine tumours (PNETs).MethodsWe retrospectively reviewed data of 125 patients operated for PNETs. Operative, pathological,and survival outcomes were compared between PNETs with and without MVI.ResultsMacrovascular venous invasion was detected in 25 of 125 PNETs (20%) presenting as tumour thrombi (n = 12) or venous wall invasion (n = 13). MVI was associated with larger tumours, a higher rate of lymph node involvement, less differentiated tumours, and a higher rate of perineural invasion. Resection of PNETS with MVI more often necessitated combined hepatic, venous and multivisceral resections, had a higher rate of intraoperative blood transfusion (p = 0.04) but similar morbidity (44% vs. 42%) and mortality (0 vs. 1%) as PNETs without MVI. PNETs with MVI had a lower median overall survival rate (60 vs. 149 months; p = 0.03). Multivariate analysis revealed that PNETs of the pancreatic head, synchronous liver metastases and higher tumour grade were prognostic factors for overall survival.ConclusionsMVI is found in more advanced PNETs. Resection of PNETs with MVI is characterized by increased transfusion rate and reduced overall survival.