title: Gastroenteropancreatic neuroendocrine tumours.
abstract: Gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) are fairly rare neoplasms that present many clinical challenges. They secrete peptides and neuroamines that cause distinct clinical syndromes, including carcinoid syndrome. However, many are clinically silent until late presentation with mass effects. Investigation and management should be highly individualised for a patient, taking into consideration the likely natural history of the tumour and general health of the patient. Management strategies include surgery for cure (which is achieved rarely) or for cytoreduction, radiological intervention (by chemoembolisation and radiofrequency ablation), chemotherapy, and somatostatin analogues to control symptoms that result from release of peptides and neuroamines. New biological agents and somatostatin-tagged radionuclides are under investigation. The complexity, heterogeneity, and rarity of GEP NETs have contributed to a paucity of relevant randomised trials and little or no survival increase over the past 30 years. To improve outcome from GEP NETs, a better understanding of their biology is needed, with emphasis on molecular genetics and disease modeling. More-reliable serum markers, better tumour localisation and identification of small lesions, and histological grading systems and classifications with prognostic application are needed. Comparison between treatments is currently very difficult. Progress is unlikely to occur without development of centers of excellence, with dedicated combined clinical teams to coordinate multicentre studies, maintain clinical and tissue databases, and refine molecularly targeted therapeutics.
authors.affiliation: Department of Gastroenterological Surgery, Yale University, New Haven, CT 06520-8062, USA. imodlin@optonline.net
authors.forename: Irvin M
authors.initials: IM
authors.lastname: Modlin
authors.forename: Kjell
authors.initials: K
authors.lastname: Oberg
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Chung
authors.forename: Robert T
authors.initials: RT
authors.lastname: Jensen
authors.forename: Wouter W
authors.initials: WW
authors.lastname: de Herder
authors.forename: Rajesh V
authors.initials: RV
authors.lastname: Thakker
authors.forename: Martyn
authors.initials: M
authors.lastname: Caplin
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Delle Fave
authors.forename: Greg A
authors.initials: GA
authors.lastname: Kaltsas
authors.forename: Eric P
authors.initials: EP
authors.lastname: Krenning
authors.forename: Steven F
authors.initials: SF
authors.lastname: Moss
authors.forename: Ola
authors.initials: O
authors.lastname: Nilsson
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.forename: Ramon
authors.initials: R
authors.lastname: Salazar
authors.forename: Philippe
authors.initials: P
authors.lastname: Ruszniewski
authors.forename: Anders
authors.initials: A
authors.lastname: Sundin
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor; D018278:Carcinoma, Neuroendocrine / Q000145:classification / Q000378:metabolism / Q000473:pathology; D005770:Gastrointestinal Neoplasms / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008967:Molecular Biology; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use
chemical_list: D014408:Biomarkers, Tumor; D013004:Somatostatin; D011505:Protein-Tyrosine Kinases