Pancreatic endocrine tumors arise from islet and gastrin-producing cells and often produce many hormones. Although these tumors develop most often in the pancreas, they may appear in other organs, particularly the duodenum, jejunum, and lung.
These tumors have two general manifestations:
Nonfunctioning tumors may cause obstructive symptoms of the biliary tract or duodenum, bleeding into the gastrointestinal tract, or abdominal masses.
Functioning tumors hypersecrete a particular hormone, causing various syndromes (see Table: Pancreatic Endocrine Tumors Pancreatic Endocrine Tumors Pancreatic endocrine tumors arise from islet and gastrin-producing cells and often produce many hormones. Although these tumors develop most often in the pancreas, they may appear in other organs... read more ). These clinical syndromes can also occur in multiple endocrine neoplasia Overview of Multiple Endocrine Neoplasias (MEN) The multiple endocrine neoplasia (MEN) syndromes comprise 3 genetically distinct familial diseases involving adenomatous hyperplasia and malignant tumors in several endocrine glands. MEN 1 involves... read more , in which tumors or hyperplasia affects two or more endocrine glands, usually the parathyroid, pituitary, thyroid, or adrenals.
Pancreatic Endocrine Tumors
Treatment for functioning and nonfunctioning tumors is surgical resection. If metastases preclude curative surgery, various antihormone treatments (eg, octreotide, lanreotide) may be tried for functioning tumors. Because of tumor rarity, chemotherapy trials have not yet identified definitive treatment. Streptozotocin has selective activity against pancreatic islet cells and is commonly used, either alone or in combination with 5-fluorouracil or doxorubicin. Some centers use chlorozotocin and interferon.
Newer chemotherapeutic regimens that include temozolomide, either alone or in combination with other agents (eg, thalidomide, bevacizumab, everolimus, capecitabine), have shown good results in small clinical trials and are under active investigation in large prospective clinical trials.