title: Expression Pattern of CDX2, Estrogen and Progesterone Receptors in Primary Gastroenteropancreatic Neuroendocrine Tumors and Metastases.
abstract: BACKGROUND
  A significant number of patients with gastroenteropancreatic neuroendocrine tumors (GEP NETs) present with metastatic disease and with unknown primary in about 15% of cases.
  
  
  METHODS
  We analyzed 163 primaries of GEP NET and 115 metastases for expression of caudal type homebox 2 (CDX2), estrogen receptor (ER), progesterone receptor (PR), somatostatin receptor 2a (SSTR2a) and Ki67.
  
  
  RESULTS
  PR was most often positive in pancreatic NET and only rarely in non-pancreatic NET (p<0.001). ER was more frequently expressed in non-pancreatic NET (p<0.001) and was more often positive in females than males (p=0.019). CDX2 was positive in all primaries of the duodenum, ileum and appendix, but was also detected in 24% of metastases with pancreatic primary. SSTR2a and Ki67 did not differ significantly between primaries and metastases.
  
  
  CONCLUSIONS
  Our data substantiate the value of PR, ER and CDX2 in GEP NET, and steroid hormone receptors, being differentially expressed in male and female patients. Differences between primaries and metastases were small but potentially relevant.
authors.affiliation: Institute of Pathology, University of Lübeck, Lübeck, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Zimmermann
authors.affiliation: Institute of Pathology, University of Lübeck, Lübeck, Germany.
authors.forename: Pamela
authors.initials: P
authors.lastname: Lazar-Karsten
authors.affiliation: Deparment of Surgery, University of Lübeck, Lübeck, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Keck
authors.affiliation: Deparment of Surgery, University of Lübeck, Lübeck, Germany.
authors.forename: Franck
authors.initials: F
authors.lastname: Billmann
authors.affiliation: Medical Clinic 1, University of Lübeck, Lübeck, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmid
authors.affiliation: Medical Clinic 1, University of Lübeck, Lübeck, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Brabant
authors.affiliation: Institute of Pathology, University of Lübeck, Lübeck, Germany christoph.thorns@uksh.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Thorns
mesh_terms: D000071616:CDX2 Transcription Factor; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D007414:Intestinal Neoplasms / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D009362:Neoplasm Metastasis; D018358:Neuroendocrine Tumors / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D017481:Receptors, Somatostatin / Q000378:metabolism; D012737:Sex Factors; D013274:Stomach Neoplasms / Q000378:metabolism*
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D019394:Ki-67 Antigen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D017481:Receptors, Somatostatin; C574734:SSTR2 protein, human
keywords: CDX2; Gastroenteropancreatic endocrine tumors; estrogen receptors; metastasis; progesterone receptors