title: Somatostatin and dopamine receptor expression in neuroendocrine neoplasms: correlation of immunohistochemical findings with somatostatin receptor scintigraphy visual scores.
abstract: BACKGROUND
  The expression of somatostatin (sstr1-5) and dopamine (DR) receptors in neuroendocrine neoplasms (NENs) facilitates diagnosis by tumour visualization with somatostatin receptor scintigraphy (SRS) and directs towards specific treatment with peptide receptor radionuclide therapy (PRRT) with radiolabelled somatostatin analogues.
  
  
  OBJECTIVE
  To investigate the co-expression of sstrs, D2R in relation to pre-operative SRSs in NENs.
  
  
  METHODS
  Prospective two-centre study.
  
  
  METHODS
  We analysed pre-operative SRS of 60 patients [44 with gastrointestinal (GI) NENs and 16 with lung NENs] and compared SRS results with immunohistochemical (IHC) reactivity for sstr2, sstr3, sstr5 in sample tissues from primary (n = 54) and metastatic (n = 27) lesions and IHC reactivity for D2R in 23 samples from primary GI-NENs lesions.
  
  
  RESULTS
  Sstr2 was the commonest sstr expressed (65·4%) and was co-expressed with sstr3 and sstr5 in 32·1% and 24·7% of the specimens, respectively. In 67 of 81 specimens (82·7%), there was concordance of sstr2 immunohistochemistry with SRS findings (P < 0·001). D2R was expressed in only 8 of 23 (34·8%) GI-NENs while was co-expressed with sstr2 in all cases. SRS grade, as per Krenning scale, was higher in metastatic foci, large-size (>2 cm) tumours and GI-NENs, whereas sstr2 intensity was greater in GI compared to lung NENs. SRS grade showed higher correlation with sstr2 (r = 0·6, P < 0·001) and D2R (r = 0·5, P < 0·001) IHC intensity scores than tumour size (r = 0·4, P < 0·001) and sstr3 (r = 0·4, P < 0·001) intensity score.
  
  
  CONCLUSIONS
  Sstr2 IHC expression and SRS are useful tools for the diagnosis and management of NENs because they display a high concordance. IHC expression of DR2 seems to be of potential clinical significance in GI-NENs tumours.
authors: Department of Pathology, "G. Gennimatas" Athens General Hospital, Athens, Greece.
authors: Evanthia
authors: E
authors: Diakatou
authors: Department of Pathophysiology, University of Athens, Athens, Greece.
authors: Krystallenia I
authors: KI
authors: Alexandraki
authors: Department of Medical Sciences, Section of Endocrine Oncology, Uppsala University, Uppsala, Sweden.
authors: Apostolos V
authors: AV
authors: Tsolakis
authors: Department of Pathology, "G. Gennimatas" Athens General Hospital, Athens, Greece.
authors: George
authors: G
authors: Kontogeorgos
authors: Department of Pathophysiology, University of Athens, Athens, Greece.
authors: Eleftherios
authors: E
authors: Chatzellis
authors: Department of Nuclear Medicine, Alexandra Hospital, Athens, Greece.
authors: Anastasia
authors: A
authors: Leonti
authors: Department of Pathophysiology, University of Athens, Athens, Greece.
authors: Gregory A
authors: GA
authors: Kaltsas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007205:Indium Radioisotopes; D008175:Lung Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism; D011446:Prospective Studies; D011877:Radionuclide Imaging / Q000379:methods; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D017481:Receptors, Somatostatin / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013004:Somatostatin
chemical_list: D007205:Indium Radioisotopes; D017448:Receptors, Dopamine D2; D017481:Receptors, Somatostatin; C574734:SSTR2 protein, human; C103631:somatostatin receptor 3; D013004:Somatostatin; C094573:somatostatin receptor 5