Abstract library

1928 results for "Small intestinal neuroendocrine tumors".
#18 Long-acting release octreotide induce complete response in type 1 gastric carcinoid tumors
Introduction: Gastric endocrine tumors (GET) are increasingly recognized due to expanding indications of upper gastrointestinal endoscopy. Often silent and benign, GET may also be aggressive when sporadic and may sometimes mimic the course of gastric adenocarcinoma. Current incidence of GETs is estimated at around 8% of digestive endocrine tumors. Yearly age-adjusted incidence is around 0.2 per population of 100,000. Gastric carcinoids (ECLomas) develop from gastric enterochromaffin-like cells (ECL cells) in response to chronically elevated gastrin. Type 1 tumors (ECLomas in the course of atrophic gastritis) may occur in conditions of achlorhydria secondary to auto-immune atrophic fundic gastritis. It occurs mostly in women and they are non-functioning tumors, typically found during upper GI endoscopy performed for dyspepsia. ECLomas present frequently as multiple polyps, usually < 1 cm in diameter in the gastric fundus. Type 1 tumors are almost exclusively benign lesions with little risk of deep invasion of the gastric parietal wall. The neoplastic ECL cells become progressively dedifferentiated with an increasing number of Ki-67 immunoreactive (IR) cell nuclei. In addition, there is a substantial decrease in argynophil and IR NE cells that can be visualized by conventional methods. ECLomas secondary to hypergastrinemia should be closely followed for signs of clinical and histopathological tumor progression. Such ECLomas deserve early, active, radical surgical treatment.
Traditionally, gastric carcinoid type 1 (GCA1s) are endoscopically or surgically removed, depending on the number, appearance and size of the tumors. Antrectomy, with surgical excision of the majority of the G cells, is thought to facilitate regression of these tumors by removing the source of excessive gastrin secretion; however, the long-term benefits of antrectomy still remain uncertain. Although proton pump inhibitors are effective in reducing hypergastrinemia-induced gastric acid hypersecretion in GCA2, they do not affect ECL-cell hyperplasia, and therefore their role in GCA1 is limited. Moreover, in selected cases, significant reduction of hypergastrinemia does not prevent development of ECL carcinoid, suggesting that, in addition to hypergastrinemia, other pathogenic or genetic factors may be involved. Treatment with somatostatin analogues (SSA) might impede ECL-cell hyperplasia by suppressing gastrin secretion and/or by a direct anti-proliferative effect on ECL cells. Treatment with SSAs in GCA1 leads to a substantial tumor load reduction, with a concomitant decrease of serum gastrin levels. Published data indicate an important anti-proliferative effect of SSA on ECL cells, providing clinical benefit and obviating, at least temporarily, the need for invasive therapies for GCA1. Morphometric studies demonstrated that, while antrectomy specifically decreased the volume of ECL cells versus the total volume of endocrine cells, octreotide reduces the overall endocrine cell volume. Although the number of treated patients is small, it has been suggested that SSA may exert important anti-proliferative effects either directly, by inhibiting ECL-cells proliferation, or indirectly through suppression of gastrin hypersecretion.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: MD Ricardo Caponero
#20 Paraneoplastic antigen Ma2 (PNMA2) auto-antibodies as biomarkers for early small intestine neuroendocrine tumors detection
Introduction: Small intestine neuroendocrine tumors (NETs) comprise well-differentiated NET (benign carcinoid), well-differentiated neuroendocrine carcinoma (malignant carcinoid) and poorly differentiated neuroendocrine carcinoma (NEC). The majority of NET patients have developed liver metastases at the time of diagnosis and surgery is then seldom curative. Novel predictive, diagnostic and prognostic markers are thus needed to improve our capabilities to diagnose and cure these tumors. We have previously identified six novel marker genes for neuroendocrine tumor cells by using Affymetrix microarrays and advanced bioinformatics. One of this markers, the paraneoplastic antigen Ma2 (PNMA2), which is normally expressed only in nervous tissue, can in the process of carcinogenesis be detected in tumors located outside the nervous system. The finding that Ma2 is expressed in small intestine neuroendocrine primary tumors and their metastases made it interesting to screen whether antibodies against Ma2 are present in the serum of NET patients.
Conference: 7th Annual ENETS Conference (2010)
Category: Basic
Presenting Author: PhD Valeria Giandomenico
Authors: Cui T, Elgue G, Li S C, Hurtig M, ...
#47 Plasma CCN2/connective tissue growth factor is associated with right ventricular dysfunction in Patients with Neuroendocrine Tumors
Introduction: Carcinoid heart disease (CHD) is a known complication of neuroendocrine tumors (NETs), particularly of those arising from the small intestine, appendix and proximal colon (previously known as mid-gut carcinoids). CHD is characterized by right heart fibrotic lesions and has traditionally been defined by the degree of valvular involvement, most commonly in the form of tricuspid regurgitation. Right ventricular (RV) dysfunction due to mural involvement may also be a manifestation. Connective tissue growth factor (CCN2) is upregulated in many fibrotic disorders. Increased tumor expression of CCN2 has been shown in patients with small intestinal NETs associated with peritoneal fibrosis. At present, its role in carcinoid heart disease is unknown.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Dr. Deidi S Bergestuen
#78 The diagnostic and prognostic value of elevated proGRP levels in well- and moderately differentiated neuroendocrine tumors
Introduction: Chromogranin A (CgA) is the most frequently used marker in well- (grade 1) and moderately (grade 2) differentiated NETs. Although CgA is a more sensitive marker than the 5-HIAA, which was widely used until the last decade, CgA has some limitations. False-positively elevated CgA may occur in renal impairment, atrophic gastritis and during treatment of proton-pump inhibitors. Progastrin-releasing peptide (proGRP) was recently reported as a promising tumor marker for small cell lung cancer. Limited data suggests that ProGRP may be a potential tumor marker in NE tumors.
Conference: 7th Annual ENETS Conference (2010)
Category: Basic
Presenting Author: Msc Catharina M Korse
#81 Gastroenteropancreatic neuroendocrine tumors (GEP-NETs): our experience in a multidisciplinary team in a university hospital
Introduction: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) have a low incidence and prevalence representing < 2% of all gastrointestinal tumors with a heterogeneous biological behavior and an often complex management.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Dr Jose Manuel Cabezas-Agricola
#106 Gastroenteropancreatic neuroendocrine tumors: single institution clinicopathological study
Introduction: Neuroendocrine cells are widely distributed throughout the body, and neoplasms from these dispersed cells can arise at many sites. They are distinguished into two broad categories: 1) Tumors identified as small cell lung carcinomas with biology and natural history of a high-grade malignancy and characteristics of small cell undifferentiated or anaplastic appearance by light microscopy. The WHO categorizes these tumors as poorly-differentiated neuroendocrine carcinomas; 2) Well-defined neuroendocrine tumors (NETs) with variable, but most lyindolent biologic behavior and characteristic well-differentiated histologic features. The majority arise in the gastrointestinal tract and collectively they are referred as gastroenteropancreatic neuroendocrine tumors (GEP/NETs). They include carcinoid tumors, pancreatic islet cell tumors (gastrinoma, insulinoma, glucagonoma, VIPoma, somatostatinoma), paragangliomas, pheochromocytomas, and medullary thyroid carcinomas. The WHO classifies the GEP/NETs as well-differentiated NETs (carcinoid tumors) if they are noninvasive and have benign behavior or uncertain malignant potential. In contrast, GEP/NETs with characteristics of low-grade malignancy with invasion of the muscularis propria or beyond, or metastases, are characterized as well-differentiated neuroendocrine carcinomas (malignant carcinoids). Pancreatic islet cell tumors, whether functioning or not, are classified as well-differentiated NETs or well-differentiated neuroendocrine carcinomas, due to the (depending on) histologic characteristics. The WHO classification for gastroenteropancreatic NETs based on stage (ie size and presence of metastases) and grade (mitotic rate, perineural and lymphovascular invasion, Ki-67 proliferative index) categorizes them as well-differentiated NETs, e.g., carcinoid tumors, or as well-differentiated neuroendocrine carcinomas.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Dr Michael M. Vaslamatzis
#112 Chromogranin A is a sensitive marker for detection of recurrence in neuroendocrine tumors
Introduction: The chromogranin family is a family of large acidic proteins which are expressed in neuroendocrine cells. There are several members in this family (Chromogranin A, B (CgA and CgB) and the secretogranins). Here, we show that CgA is an excellent marker to detect recurrence in neuroendocrine tumors.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Prof Eva Tiensuu Janson
#118 Gastrointestinal motility in patients with neuroendocrine tumors
Introduction: Diarrhea is the most common symptom in patients with intestinal neuroendocrine tumors (NET). Somatostatin analogues reduce stool frequency and may increase gastrointestinal transit time (GITT). Motility tracking system® MTS-1 (MTS) (Motilis, Switzerland) is a novel, safe, almost non-invasive and easy-to-perform method for description of gastrointestinal motility.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Tine Gregersen
#134 Gastrointestinal neuroendocrine tumors: tumor characteristics and long-term clinical outcome in the German NET registry
Introduction: Prognosis of neuroendocrine tumors (NETs) has been difficult to predict due to heterogenous tumor biology, various classification systems, and lack of reliable and recent data due to the rarity of these tumors.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Dr. Ulrich-Frank Pape
Authors: Maasberg S, König A, Rinke A, Anlauf M, ...
#141 Incidence of second primary tumors in patients with neuroendocrine tumors
Introduction: Based on epidemiological data from SEER 1950-1999, 22.4% cases of non-carcinoid second primary tumors have been described in patients diagnosed with neuroendocrine tumors. The incidence of this type of tumors varies, depending on the series assessed.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: MD Juan Manuel OConnor
Authors: Pesce V, OConnor J, Mendez G, Bestani C, ...