title: Diagnosis and treatment of gastroenteropancreatic neuroendocrine tumors: current data on a prospectively collected, retrospectively analyzed clinical multicenter investigation.
abstract: BACKGROUND
  The aim of this prospectively collected, retrospectively analyzed clinical investigation was to describe "unmasked" clinical symptoms and methods of diagnosis, treatment, and short-term follow-up of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) diagnosed during 1 year in Austria.
  
  
  METHODS
  In total, 277 patients with GEP-NETs were documented. All tumors were immunhistochemically defined according to recently summarized criteria (World Health Organization, European Neuroendocrine Tumour Society). A standardized questionnaire comprising 50 clinical and biochemical parameters (clinical symptoms, mode of diagnosis, treatment, follow-up) was completed by attending physicians.
  
  
  RESULTS
  The most common initial symptoms were episodes of abdominal pain, diarrhea, weight loss, gastrointestinal bleeding, flushing, and bowel obstruction. Overall, 48.1% of tumors were diagnosed by endoscopy, 43.7% were diagnosed during surgery, 5% were diagnosed by fine-needle aspiration of the primary or metastases, and 2.5% were diagnosed during autopsy; 44.5% of tumors were not suspected clinically and were diagnosed incidentally during various surgical procedures. Overall, 18.7% of tumors were removed endoscopically and 67.6% were removed surgically; 13.7% of patients were followed without interventional treatment. Endoscopic or surgical intervention was curative in 81.4% of patients and palliative in 18.6% of patients. At the time of diagnosis, information on metastasis was available in 83.7% of patients with malignant NETs. Lymph node or distant metastases were documented in 74.7% of patients. In 19.3% of patients, 41 secondary tumors were documented, with 78.0% classified histologically as adenocarcinomas.
  
  
  CONCLUSIONS
  This investigation summarizes the clinical presentation and current practice of management of GEP-NETs and thereby extends the understanding and clinical experience.
authors.affiliation: Section of Endocrine Surgery, Division of General Surgery, Department of Surgery, Medical University of Vienna, Währinger Gür, Austria. martin.niederle@meduniwien.ac.at
authors.forename: Martin B
authors.initials: MB
authors.lastname: Niederle
authors.forename: Bruno
authors.initials: B
authors.lastname: Niederle
mesh_terms: D001317:Austria / Q000453:epidemiology; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000453:epidemiology; D018450:Disease Progression; D006801:Humans; D007078:Ileal Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D007414:Intestinal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D007580:Jejunal Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D015337:Multicenter Studies as Topic; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D011795:Surveys and Questionnaires