Clinicopathological Characteristics and Prognosis-Related Factors of Resectable Pancreatic Neuroendocrine Tumors: A Retrospective Study of 104 Cases in a Single Chinese Center

OBJECTIVE: The purpose was to describe the clinicopathological characteristics of pancreatic neuroendocrine tumors (pNETs) and evaluate prognosis-related factors in potentially resectable pNETs. METHODS: The clinical data of 104 patients with pNETs who underwent surgery were retrospectively analyzed. RESULTS: The mean (SD) age was 49.8 (14.6) years. The percentages of TNM stages I, II, III, and IV tumors were 25.0%, 44.2%, 22.1%, and 8.7%, respectively. Twenty-seven cases were functional. Nonfunctional pNETs were more common in patients with large tumors, advanced age, higher mitotic count, neural invasion, extrapancreatic organ invasion, liver metastases, and advanced staging (P < 0.05). The 5-year overall survival rate was 93%. The relapse rate was 28.6% (28/98), and the mean (SD) relapse time was 38.7 (31.7) months. Reduced survival rate was associated with older patients (>60 years) (P = 0.026), patients with a higher Ki-67 index (>2%) (P = 0.024), regional lymph node metastases (P = 0.033), liver metastases (P = 0.015), neural invasion (P = 0.017), necrosis (P = 0.042), and major vascular invasion (P = 0.023). Age of more than 60 years (P = 0.047; hazard ratio [HR], 5.2), major vascular invasion (P = 0.030; HR, 5.8), and a Ki-67 index greater than 2% (P = 0.008; HR, 10.3) were independent predictors. CONCLUSIONS: Nonfunctional pNETs were more common with aggressive clinical presentation. Age of more than 60 years, major vascular invasion, and a Ki-67 index greater than 2% were independent predictive factors. Patients who underwent a potentially curative resection seemed to achieve long-term survival.