Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors.

BACKGROUND: Nonfunctioning pancreatic neuroendocrine tumors (NFpNET) present with distant metastases in up to 50% of patients. It is unknown whether removal of the primary tumor in patients with NFpNET and metastases is beneficial. METHODS: We used the Surveillance, Epidemiology, and End Results database to identify patients with NFpNET and distant metastases. The primary outcome measure in this study was overall survival. RESULTS: We identified 882 patients with metastatic NFpNET who had survival data; 303 (34%) patients had operative removal of their primary tumor of which 243 (80%) were grade I or II. Median survival of patients undergoing resection of the primary site was 65 (95% confidence interval 60-86) versus 10 (8-12) months for those without resection (P < .0001). Patients diagnosed after 2003 (n = 625, 71%) were more likely to undergo an operation than those diagnosed earlier (P = .001). Multivariable analysis showed that a lesser tumor grade (P < .0001), younger age (P < .0001), diagnosis during or after 2003 (P = .0003), tumor site in the body/tail (P = .009), and operative resection of the primary tumor site (P < .0001) were associated with prolonged survival of patients with NFpNET and distant metastases. CONCLUSION: This study suggests that resection of the site of the primary NFpNET is associated with greater survival in patients with distant metastases and could therefore be considered as a additional treatment option in this patient population.

Feasibility of Radio-Guided Surgery with 68Gallium-DOTATATE in Patients with Gastro-Entero-Pancreatic Neuroendocrine Tumors.

BACKGROUND: Surgery is the only definitive therapy for gastro-entero-pancreatic neuroendocrine tumors (GEPNETs), and achieving complete tumor resection is an important prognostic factor. Radiopharmaceuticals such as (68)Ga-DOTA peptides have been developed that offer superior accuracy for localization of GEPNETs. The study aim was to determine the feasibility of radio-guided surgery (RGS) using (68)Ga-DOTATATE in patients with primary and recurrent GEPNETs. METHODS: Fourteen patients with GEPNETs were enrolled onto a prospective study to determine the feasibility of RGS with (68)Ga-DOTATATE. Findings from preoperative imaging, intraoperative exploration, RGS, and pathology were analyzed. RESULTS: The median decay corrected target count rate was 172.6 (range 28.15-2341) for tumors, with a tumor-to-background ratio (TBR) of 4.46 (range 1.6-43.56). The median lesion size was 1.55 (range 0.5-15) cm. There was no significant correlation between preoperative imaging maximum standardized uptake value (SUVmax) of the lesions and TBR (Spearman r = - 0.01, p = 0.9), TBR and tumor size (Spearman r = 0.29, p = 0.14), and SUVmax and tumor size (Spearman r = 0.22, p = 0.28). The probe showed correct identification for gastric and small intestine neuroendocrine tumor (NET), including lymph node metastasis in 17 (81.0 %) of 21 cases, with a median TBR of 3.5 (1.6-40.2). For pancreatic NETs and lymph node metastasis, 16 (66.7 %) of 24 were correctly identified by RGS. CONCLUSIONS: Our study shows that RGS with (68)Ga-DOTATATE is feasible and correctly confirms bowel NETs and metastatic mesenteric lymph nodes. Further studies are needed to determine the benefit of RGS with (68)Ga-DOTATATE.