Pancreatic neuroendocrine tumors: Twenty years’ experience of 100 patients at a single center.

Abstract

179 Background: Pancreatic neuroendocrine tumors (NETs) are rare neoplasms that exhibit a variety of diverse morphological, functional and behavioral characteristics. However, only a few reports have evaluated large case series of pancreatic endocrine tumors. Methods: We conducted a retrospective review of 100 consecutive patients with pancreatic NETs diagnosed pathologically and treated at the National Cancer Center Hospital between 1991 and 2010. Results: The characteristics of the 100 patients were as follows: male, 49; female, 51; median age, 55 years. Fourteen patients gave a history of endocrine symptoms at the time of diagnosis. The primary tumors arose in the head, body and tail of the pancreas in 54, 25 and 21 patients, respectively. According to the 2010 grading classification of the World Health Organization, 11 patients were classified as having NET G1, 44 as having NET G2 and 29 as having NEC. The five-year survival rates of the patients with NET G1, NET G2 and NEC were 91%, 78% and 12%, respectively. The five-year survival rates of the patients with stage I, II and III, and IV disease classified according to the American Joint Committee on Cancer (AJCC) were 100%, 68% and 9%, respectively. Distant metastases occurred in 18% percent of the NET G1 patients, 39% of the NET G2 patients and 83% of the NEC patients. Treatment was undertaken by surgical resection in 82%, 59% and 24% of patients with NET G1, NET G2 and NEC, respectively. The five-year survival rates of the patients with NET G1, NET G2 and NEC after radical surgery were 100%, 91% and 36%, respectively. Among the 33 patients treated by systemic chemotherapy, the median survival period was 22.9 months in the patients with NET G1/G2 and 6.6 months in those with NEC. A multivariate analysis identified lower age, good performance status (PS) and lower histopathologic grade as independent favorable prognostic factors. Conclusions: Patients with NET G1, G2 treated by surgical resection had a good prognosis. Most patients with NEC exhibited distant metastases and had a poor prognosis. Histopathologic grade is an important factor for selecting the appropriate treatment strategy and predicting the prognosis in patients with pancreatic NETs.