Approximately 90% of appendiceal carcinoids measure smaller than 1 cm and are not located in the appendiceal base; these tumors can be consistently cured by appendectomy.
Appendiceal carcinoids larger than 2 cm require right-sided hemicolectomy and ileocecal lymphadenectomy because of the significant risk of metastasis. For tumors measuring 1 to 2 cm, treatment is controversial, but hemicolectomy may be appropriate if there is invasion in the mesoappendix, if there is residual tumor in the resection margins, or in the presence of lymph node metastases. For same-size lesions confined to the appendiceal wall, appendectomy alone may carry a low risk for metastases. Acceptable indications for hemicolectomy may include operative specimens that show high proliferative activity (high Ki67 index), high mitotic index, or signs of angioinvasion, but evidence is limited and histologic parameters for risk evaluation in appendiceal carcinoids measuring 1 cm to 2 cm requires definition.[1-3] Follow-up should be considered in patients for whom elevated serum chromogranin A may indicate the need for extended operation. Although survival is excellent with locoregional tumor, 10-year survival is approximately 30% with distant metastases.
Goblet cell carcinoid or adenocarcinoid is a rare variant of appendiceal carcinoid with mixed endocrine and exocrine features. Often presenting with a diffusely inflamed appendix and occurring in patients at a later age (~50 years), these tumors are aggressive, often with peritoneal and ovarian metastases, and occasionally appearing as mucinous adenocarcinoma.[2-4] They do not express somatostatin receptors and cannot be visualized by 111-Indium octreotide scintigraphy. Goblet cell carcinoids are treated with right-sided hemicolectomy and lymphadenectomy in combination with chemotherapy. For disseminated tumors, aggressive surgical reduction including peritonectomy and oophorectomy may be required. Goblet cell carcinoids have a 10-year survival rate of approximately 60%.Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with localized gastrointestinal carcinoid tumor and regional gastrointestinal carcinoid tumor. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.References
- Akerström G, Hellman P: Surgery on neuroendocrine tumours. Best Pract Res Clin Endocrinol Metab 21 (1): 87-109, 2007. [PUBMED Abstract]
- Goede AC, Caplin ME, Winslet MC: Carcinoid tumour of the appendix. Br J Surg 90 (11): 1317-22, 2003. [PUBMED Abstract]
- Stinner B, Rothmund M: Neuroendocrine tumours (carcinoids) of the appendix. Best Pract Res Clin Gastroenterol 19 (5): 729-38, 2005. [PUBMED Abstract]
- Akerström G, Hellman P, Hessman O: Gastrointestinal carcinoids. In: Lennard TWJ, ed.: Endocrine Surgery. 4th ed. Philadelphia, Pa: WB Saunders Ltd, 2009, pp 147-76.