Endocrine tumors of the pancreas

Purpose of review: Neoplasms of the endocrine pancreas, commonly referenced as pancreatic islet cell tumors, are rare, often well differentiated endocrine neoplasms, whose biology remains poorly characterized. This article reviews the current clinical management of pancreatic islet cell tumors and describes the molecular events that have been studied to guide future therapies of these peculiar neoplasms. Recent findings: While some islet cell tumors arise in association with the MEN-1 syndrome, the majority of these neoplasms are sporadic lesions whose underlying genetic and molecular events remain largely unknown. Recent work has identified changes in gene expression occurring in metastatic and non-metastatic islet cell tumors, which appear to correlate with the occurrence of lymph node and liver metastases. Epigenetic alterations of select tumor suppressor genes may influence patient survival, and the presence of gene promoter methylation may be used as a prognostic marker system. In addition, multiple molecular alterations, including changes in expression of cellular proteins with migratory, cell cycle or angiogenic functions, have been demonstrated to influence islet cell tumor growth, invasion and metastatic spread. Summary: Understanding the molecular events underlying the biology of pancreatic islet cell tumors will aid the development of accurate prognostic markers and will guide improved therapeutic modalities in the future.