Surgical treatment of non-functioning pancreatic neuroendocrine tumors: current controversies and challenges

Abstract. There has been a rising trend in the incidence and prevalence of non-functioning pancreatic neuroendocrine tumors (NFPanNETs). While a significant number of the newly diagnosed NFPanNETs are asymptomatic, a majority of patients will present with liver metastasis (LM) at the time of diagnosis. Surgical resection remains the only curative treatment, especially for localized NFPanNETs. While a majority of small NFPanNETs are indolent, some are not. This heterogeneity in tumor biology presents the surgeon with the unique challenge of determining which patient will benefit from surgery, given the morbidity of pancreatic surgery. There has been a recent push for a more aggressive approach to the care of these patients, given the emergence of data supporting such measures. However, the risk of over or under treatment has generated immense debate amongst experts in the field. The heterogeneity of current practice guidelines and institutional practices around the world is a reflection of the disparate opinion on the management of NFPanNET. In this review, we set out to examine the evidence regarding some of the most controversial and challenging aspects of the surgical treatment of NFPanNET. We evaluate the following questions; should patients with small NFPanNETs ≤ 2 cm in size be resected; should patients with metastatic NFPanNETs undergo surgical debulking, and should there be resection of the primary tumor in the setting of non-resectable metastatic disease? Although there are currently no Level 1 data to answer these questions conclusively, we believe that the current literature supports a more aggressive approach to the management of NFPanNET