About Carcinoid Tumours (carcinoids)
Contents
Overview
About Carcinoid Tumors
Title 3
Overview
About Carcinoid Tumors
Title 3
Carcinoid tumours, or carcinoids, originate in hormone-producing cells of the gastrointestinal (GI) tract (i.e., esophagus, stomach, small intestine, colon), the respiratory tract (i.e., lungs, trachea, bronchi), the hepatobiliary system (i.e., pancreas, gallbladder, liver), and the reproductive glands (i.e., testes, ovaries).
The most common site of origin is the GI tract and carcinoid tumors often develop in the appendix, the rectum, and the lower sections of the small intestine (i.e., the jejunum and the ileum). The large tubes that lead from the windpipe to the lungs (bronchi) are other common sites of origin.
Carcinoids are classified as neuroendocrine tumors. They develop in peptide- and amine-producing cells, which release hormones in response to signals from the nervous system. Excessive amounts of these hormones cause a condition called carcinoid syndrome in approximately 10% of patients with carcinoid tumors.
Carcinoids are slow growing and tumors with the same site of origin often have different characteristics and growth patterns. They can be subdivided according to the following:
* Cellular growth pattern (e.g., trabecular, glandular, undifferentiated, mixed)
* Hormones produced (e.g., bradykinin, serotonin, histamine, prostaglandins)
* Site of origin ? foregut (respiratory tract, pancreas, stomach, first section of the small intestine [duodenum]), midgut (jejunum, ileum, appendix, diverticulum, ascending colon), or hindgut (transverse colon, descending colon, rectum)
* Hormones produced (e.g., bradykinin, serotonin, histamine, prostaglandins)
* Site of origin ? foregut (respiratory tract, pancreas, stomach, first section of the small intestine [duodenum]), midgut (jejunum, ileum, appendix, diverticulum, ascending colon), or hindgut (transverse colon, descending colon, rectum)
About Carcinoid Tumors
Carcinoids are tumors of neuroendocrine origin. Approximately 85% of carcinoid tumors develop in the gastrointestinal tract between the stomach and the rectum. Approximately half of these originate in the appendix, and may metastasize to the liver, while the remaining half develop in the intestine, rectum and lung. Approximately 6,000-7,000 cases of carcinoid cancer are diagnosed in the U.S. annually and their incidence has been increasing over the past 30 years. It is common for more than one tumor to develop in the small intestine and the presence of a carcinoid tumor increases the probability of other cancers in the digestive system.
Carcinoid tumors often release certain hormones into the bloodstream that cause symptoms such as facial flushing, wheezing, diarrhea, and a fast heartbeat. These symptoms are grouped together and called the "carcinoid syndrome." Carcinoid tumors can release hormonally active peptides into the blood that cause symptoms throughout the body, as contrasted with other tumor types that produce symptoms at the site of the primary tumor or its metastases. Chemotherapy may be indicated in patients with aggressive tumors, progressive liver metastases, partial or complete intestinal obstruction, or severe symptoms uncontrollable by other treatment methods.
Carcinoid tumors tend to be over-represented in certain populations, suggesting a genetic component in the development of the disease. For more information on this study, visit the Clinical Trials section of EntreMed's web site at http://www.entremed.com.
Latest Research
Carcinoid Tumour Research
