Pattern and Clinical Predictors of Lymph Node Involvement in Pancreatic Neuroendocrine Tumors (PanNETs).

Introduction: Pancreatic neuroendocrine tumors (PanNETs) are often indolent neoplasms without pathological lymph node (LN) metastasis (pN1). Aim(s): To construct a model for predicting the risk of pN1 prior to surgical resection. Materials and methods: The databases from the Surgical Department of the University of Verona and the Beaujon Hospital were queried. Data of 194 patients with resected (R0 or R1), nonfunctioning PanNET (1993-2009) were reviewed. Multiple logistic regression analysis was performed. Results: Metastases were present in the dissected LNs of 58 patients (30%). The 5-year disease free survival for patients with pN1 was significantly lower than for pN0 patients (66% v. 93%, P 4 cm (OR 2.5, P=0.012) was an independent predictor of pN1 (second model). The area under the ROC curve for the first and the second model resulted to be 80% and 74%, respectively. Conclusion: Patients with PanNET-G1, in the absence of radiological node involvement, have a very low risk of pN1. When a preoperative cytological diagnosis is not achieved, then radiological size of the lesion is a powerful alternative predictor of pN1. [ABSTRACT FROM AUTHOR]