Surgical strategies and predictors of outcome for malignant neuroendocrine tumors of the pancreas

Background and aim: Neuroendocrine pancreatic carcinomas are rare and little information on factors influencing the clinical course and prognosis is presently available. The aim of this study was to retrospectively review all patients who underwent pancreatic resection for malignant neuroendocrine tumor of the pancreas at the one department from 1989 to 2003. Methods: Eleven male and eight female patients with a mean age of 51 years (range 13-76 years) underwent surgery for malignant neuroendocrine tumor of the pancreas. The prognostic relevance for long-term survival was investigated for intrapancreatic localization of the primary, histological classification including proliferation index (Ki67), lymph node involvement, surgical treatment and long-term survival after resection. The clinical course after resection was also evaluated. Statistical analysis was performed using multivariate analysis and Kaplan-Meier method. Results: Functional or non-functional tumors occurred in six (32%) and 13 (68%) patients, respectively. The tumors were located in the pancreatic head in 10 patients (53%), body in three (15%) and tail in two (11%). Multilocular tumors were found in five (26%). Surgical procedures performed were six pylorus preserving pancreaticoduodenectomies (32%), four standard pancreaticoduodenectomies (21%), four distal pancreatectomies (21%), three total pancreatectomies (15%) and two segmental resections (11%). Multivariate analysis showed sex (P = 0.018), Ki67 proliferation index (P = 0.023), tumor diameter (P = 0.02) and tumor site (P = 0.011) as significant predictors of outcome. Conclusion: Malignant neuroendocrine tumors of the pancreas are associated with poor prognosis. Surgical resection is an appropriate and safe procedure with low morbidity rates. The prognosis seems to be determined by various biological factors. However, with regard to the principles of surgical oncology, tumor-free resection margins are important and radical surgical procedures are justified in selected patients.