Metastatic Carcinoid Tumors: A Clinical Review

Abstract

Carcinoid tumors are neuroendocrine tumors derived from enterochromaffin cells, which are widely distributed in the body. They can originate from any location in the body, but they are traditionally described as originating from the foregut, midgut, and hindgut. Although the overall incidence of carcinoid tumors appears to have increased in the past decades, the prognosis for patients with metastatic carcinoid tumors has improved during the last decade. Due to longer survival times, complications, such as carcinoid heart disease, and new metastatic patterns, like skin and bone metastases, may become more important features of carcinoid disease. Therapy focused on these complications should be part of the management. Combining new diagnostic and treatment modalities in metastatic carcinoid patients may result in better quality of life and longer survival times. The increasing number of therapeutic options and diagnostic procedures requires a multidisciplinary approach, with decisions made in multidisciplinary meetings focused on "tailor-made" therapy based on patients' specific conditions. Because carcinoid tumors are uncommon, effort should be made to treat these patients in specialized centers and for these centers to join together in multicenter studies. The Oncologist 2005;10:123-131The Oncologist 2005;10:123-131 www.TheOncologist.com

Neuroendocrine tumors: a registry of 1000 patients

“…The wide distribution and the varying clinical presentations, as well as the endocrine phenomena usually accompanying those tumors, hamper the efforts to establish sound and extensive experience in any single institution. Moreover, the relative rarity of neuroendocrine tumors clearly restricts the efforts of researchers to complete significant studies to define recommended approaches to all situations [2][3][4] . Since the early eighties, renewed interest in the study of neuroendocrine tumors emerged in different centers, with specialists teaming up to perform an ever-growing number of studies, mostly in the treatment of advanced and metastatic stages 5 .…”

A 92-gene cancer classifier predicts the site of origin for neuroendocrine tumors

“…The site of origin for neuroendocrine carcinoma has become increasingly important for grading/staging purposes, 1,2 for new clinical management guidelines, [3][4][5][6][7] and for primary site-specific targeted therapy. [8][9][10] When a primary site cannot be identified, tumors generally are treated according to the presumed aggressiveness of the tumor, as determined by a combination of the tumor grade [11][12][13][14] and available clinical and radiographic information about tumor metabolism. 14 Because neuroendocrine carcinoma subtyping for site of origin is critical for clinical management, research has been dedicated to finding site and subtype-specific diagnostic markers.…”

“…[8][9][10] When a primary site cannot be identified, tumors generally are treated according to the presumed aggressiveness of the tumor, as determined by a combination of the tumor grade [11][12][13][14] and available clinical and radiographic information about tumor metabolism. 14 Because neuroendocrine carcinoma subtyping for site of origin is critical for clinical management, research has been dedicated to finding site and subtype-specific diagnostic markers. [15][16][17][18] Several biomarkers have been utilized to determine tumor subtype.…”

“…Despite extensive clinicopathological investigation, however, it is estimated that up to 10% of patients with differentiated neuroendocrine carcinoma will have an unknown primary site. 14 Traditionally, pathologists have used panels of protein-based immunohistochemical stains for tumor classification, but the potential advantage of molecular tests is readily apparent. In recent years, RNA expression-based classification of tumors has become an attractive standardized approach to aiding in the diagnosis and subclassification of tumors [19][20][21][22][23][24][25] and for individualized therapy applications.…”

Neuroendocrine Tumor in the Lung of a Captive Black Spider Monkey (Ateles paniscus)

“…For this reason, they can be found at almost any location in the body but generally originate from the foregut, midgut, and hindgut [7,8,16]. In humans, the incidence of NE tumors are approximately 2.5 per 100,000 people per year [9].…”