Multicenter retrospective study of tumor recurrence risk in patients with lymph node-negative pancreatic neuroendocrine tumors

Lymph node (LN) metastasis is a strong predictor of tumor recurrence following pancreatectomy for localized pancreatic neuroendocrine tumors (PanNETs). However, most patients lack LN metastasis, and yet many tumors recur. A retrospective case-control study at 5 centers in the USA investigated clinicopathologic determinants of disease recurrence in LN-negative PanNETs. In this study of 770 patients, the rate of tumor recurrence was 10.6% at a median of 32.4 months after surgery. An internally and externally validated model, including male gender, tumor size greater than 3 cm, WHO grade 2 or greater, and lymphovascular invasion, was developed to stratify patients into low (2.4%), moderate (9.0%), and high (27.7%) recurrence risk following pancreatectomy. The authors conclude that these findings provide a risk-adapted framework for postoperative surveillance and therapeutic strategies in patients with LN-negative PanNETs.