Follow-Up for Node-Negative Patients After Resection for Pancreatic Neuroendocrine Tumor

Ventin et al present a retrospective, case-control study that included patients who underwent curative-intent pancreatectomy for localized pancreatic neuroendocrine tumors (PanNETs) across 5 high-volume US institutions. This collaborative group (PANDA) set themselves the task of identifying clinicopathologic determinants of disease recurrence in lymph node (LN)–negative PanNETs on the basis that some of these patients have a notable risk of recurrence, yet it is unclear which patients require surveillance. This collaborative effort should be commended. These are leading institutions in the field and this analysis adds to the literature in terms of risk stratification for recurrence. They have defined 3 risk was 2.4%, 9%, and 27.7%, respectively. Of the 4 independent clinic pathological factors identified using the LN ratio–pancreatic neuroendocrine tumors score, there were 2 that were predictable: World Health Organization grade 2 or higher and tumor size larger than 3 cm. Lymphovascular invasion and male gender were also risk factors. The association of lymphovascular invasion and nodal positivity with outcomes, such as survival and recurrence, has been much studied. This report adds evidence to the association of nodal positivity or lymphovascular invasion and oncologic outcomes. Yet, results remain very diverse, with some studies showing an association of lymphovascular invasion with disease-free or overall survival and others showing no such association, or just for specific subgroups, such as certain sizes or tumor stages. This report makes a compelling case as a new prognostic model for LN negative patients. The authors propose surveillance plans based on the defined risk