Neuroendocrine tumors (NET) arise from cells throughout the nervous and endocrine systems (eg, cells of the pancreas, parathyroid, adrenal, and pituitary glands). They may also arise from the calcitonin-producing cells of the thyroid glands.1
NET can progress for 5 to 7 years before correct diagnosis2
Patients with NET may or may not have symptoms caused by hormonal hypersecretion.2 NET may grow while silent or nonspecific symptoms lead to misdiagnosis.3 Some common misdiagnoses include4*:
- IBS/IBD: 54%
- Food intolerances: 26%
- Psychiatric disorders: 25%
- Other: 20%
- Other GI symptoms: 13%
- Menopause: 8%
NET is often misdiagnosed. Some patients are even given more than one incorrect diagnosis.4
Progression can precede diagnosis
Significant disease progression may occur during the period of delayed diagnosis.4 Many are not diagnosed until the hormonal secretions of the metastases start to cause debilitating symptoms that may be associated with worse outcomes.2
- Up to half of all NET patients with histologically defined disease have distant metastases at diagnosis5
- Correct diagnosis is often delayed until after patients develop symptoms5,6
- Metastatic disease can precede symptomatic disease1-3
- The median survival for patients with well-differentiated (Grade 1/Grade 2) NET with distant metastases was 33 months5†
- Median survival can vary enormously, depending on the location of the tumor (ie, 5 months for colonic NET)5
Gastrointestinal and pancreatic NET
The most common type of NET are gastrointestinal and pancreatic NET (GI NET and pNET), which occur in the digestive tract, primarily in the stomach, intestines, or pancreas.7
Common gastrointestinal and pancreatic NET are listed below8-11:
| Carcinoid tumors | Arise from neuroendocrine cells in the appendix, ileum, rectum, and bronchus |
| Insulinomas | A type of pancreatic islet cell tumor that secretes excess insulin and may occasionally secrete other hormones, including gastrin, ACTH, and glucagons |
| Gastrinomas | Gastrin-releasing tumors of the pancreatic islet cell or duodenum associated with Zollinger-Ellison syndrome |
| Vasoactive intestinal peptide (VIP) tumors (VIPomas; Verner-Morrison syndrome) | Primarily occur in pancreatic islet cells, although they may also occur in the lung or liver. These tumors secrete an excess of VIP, a 28-amino acid peptide hormone |
| Glucagonomas | A type of pancreatic islet cell tumor that secretes an excess of glucagon |
| Somatostatinomas‡ | A rare type of tumor that occurs in the pancreas and small intestine, and which is characterized by diabetes mellitus, gallbladder disease, weight loss, and steatorrhea |
* In a study of 115 patients, incorrect diagnoses given to patients with abdominal carcinoid tumors were collected. Some patients were given more than one incorrect diagnosis.4
† Study details: The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program registries were searched to identify NET cases from 1973-2004, using the SEER staging system for analysis (N=35,618). Associated population data were used for incidence and prevalence analyses.5
‡ Sandostatin® LAR® is not approved to treat somatostatinomas.
References:
1. Vinik AI, Woltering EA, O’Dorisio TM, Go VLW, Mamikunian G. Neuroendocrine Tumors: A Comprehensive Guide to Diagnosis and Management. 5th ed. Inglewood, CA: Inter Science Institute; 2012. 2. Modlin IM, Oberg K, Chung DC, et al. Gastroenteropancreatic neuroendocrine tumours. Lancet Oncol. 2008;9:61-72. 3. Modlin IM, Kidd M, Latich I, Zikusoka MN, Shapiro MD. Current status of gastrointestinal carcinoids. Gastroenterology. 2005;128:1717-1751. 4. Toth-Fejel S, Pommier RF. Relationships among delay of diagnosis, extent of disease, and survival in patients with abdominal carcinoid tumors. Am J Surg. 2004;187:575-579. 5. Yao JC, Hassan M, Phan A, et al. One hundred years after "carcinoid": epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States. J Clin Oncol. 2008;26:3063-3072. 6. Vinik A, Moattari AR. Use of somatostatin analog in management of carcinoid syndrome. Dig Dis Sci. 1989;34(suppl 3):14S-27S. 7. Oberg K, Jelic S; on behalf of the ESMO Guidelines Working Group. Neuroendocrine gastroenteropancreatic tumors: ESMO clinical recommendations for diagnosis, treatment and follow-up. Ann Oncol. 2008;19(suppl 2):ii104-ii105. 8. Jensen RT, Doherty GM. Carcinoid tumors and the carcinoid syndrome. In: DeVita VT Jr, Hellman S, Rosenberg SA, eds. Cancer: Principles and Practice of Oncology. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004:1559-1574. 9. Warner RRP. Enteroendocrine tumors other than carcinoid: a review of clinically significant advances. Gastroenterology. 2005;128:1668-1684. 10. Adam N, Lim SS, Ananda V, Chan SP. VIPoma syndrome: challenges in management. Singapore Med J. 2010;51:e129-e132. 11. Liu T-H, Tseng H-C, Zhong S-X, Chen J, Cui Q-C. Insulinoma: an immunocytochemical and morphologic analysis of 95 cases. Cancer. 1985:56:1420-1429.