Some rare forms of pancreatic cancer form from the abnormal growth of hormone-producing cells in the pancreas called islet cells. These tumors are known as pancreatic neuroendocrine tumors (pancreaticNETs or PNETs), pancreatic endocrine tumors or islet cell tumors.
Islet cells are the endocrine cells in the pancreas that produce and secrete the hormones insulin, glucagon and somatostatin into the bloodstream. Insulin and glucagon are the two main pancreatic hormones. Insulin lowers blood sugar levels while glucagon raises blood sugar levels. Together, these two main hormones work to maintain the proper level of sugar in the blood. Somatostatin regulates the levels of a variety of other hormones in the blood.
Pancreatic neuroendocrine tumors account for less than 5% of all pancreatic tumors. They may be benign or malignant and they tend to grow slower than exocrine tumors. Pancreatic neuroendocrine tumors are either functional (produce hormones) or nonfunctional (produce no hormones). Most functional neuroendocrine tumors are benign. However, 90% of nonfunctional neuroendocrine tumors are cancerous. The following table describes the different types of pancreatic neuroendocrine tumors.
|Gastrinoma (Zollinger-Ellison Syndrome)||Gastrinomas overproduce gastrin. Most are malignant or have the ability to become malignant. When this tumor is inherited as part of a genetic syndrome called Multiple Endocrine Neoplasia Type 1 (MEN1) (see below), multiple tumors may be found in the head of the pancreas and/or the duodenum.|
Glucagonomas overproduce glucagon. They are usually large, often metastasize and about 70% are malignant. They are commonly found in the body and tail of the pancreas.
|Insulinoma||Insulinomas overproduce insulin. They are the most common pancreatic neuroendocrine tumors. They tend to be small and hard to find. Most of them are benign.|
|Nonfunctional Islet Cell Tumor||Nonfunctional islet cell tumors are usually malignant. They are hard to detect.|
|Somatostatinoma||Somatostatinomas overproduce somatostatin. They are extremely rare and usually very large. They can occur anywhere in the pancreas and in the duodenum. They vary in their potential to become malignant.|
|Vasoactive Intestinal Peptide-Releasing Tumor (VIPoma or Verner-Morrison Syndrome)||VIPomas overproduce vasoactive intestinal peptide (VIP). These tumors are usually located in the body and tail of the pancreas. Two-thirds of VIPomas are found in women. The syndrome is also known as Watery Diarrhea and Hypokalemia Achlorhydria (WDHA) Syndrome.|
Information provided by the Pancreatic Cancer Action Network, Inc. (“PanCAN”) is not a substitute for medical advice, diagnosis, treatment or other health care services. PanCAN may provide information to you about physicians, products, services, clinical trials or treatments related to pancreatic cancer, but PanCAN does not recommend nor endorse any particular health care resource. In addition, please note that any personal information you provide to PanCAN’s associates during telephone and/or email communications may be stored and used to help PanCAN achieve its mission of assisting patients with, and finding cures and treatments for, pancreatic cancer. Stored constituent information may be used to inform PanCAN programs and activities. Information also may be provided in aggregate or limited formats to third parties to guide future pancreatic cancer research and treatment efforts. PanCAN will not provide personal directly identifying information (such as your name or contact information) to such third parties without your prior written consent unless required or permitted by law to do so.