title: CD117/KIT expression in pancreatic adenocarcinoma.
abstract: OBJECTIVE
  CD117/KIT overexpression is common in neoplasms such as gastrointestinal stromal tumors and predicts clinical response to tyrosine kinase inhibitors. Pancreatic adenocarcinoma has a poor prognosis, and therefore, targeted molecular therapy may be beneficial. Marked differences in the incidence of CD117/KIT expression have been reported in pancreatic adenocarcinoma. The aim of this study was to test the hypothesis that CD117/KIT expression is unusual in pancreatic adenocarcinoma.
  
  
  METHODS
  CD117/KIT immunohistochemistry was performed on 23 archival pancreatic adenocarcinoma samples using 2 primary antibodies.
  
  
  RESULTS
  Satisfactory internal and external positive control labeling was achieved for both primary antibodies. No tumor cell labeling was identified using one primary antibody, whereas all cases showed cytoplasmic CD117/KIT staining with the second. However, CD117/KIT expression was also identified using the latter within nuclei and benign pancreatic epithelium, suggesting that artifactual staining was occurring.
  
  
  CONCLUSIONS
  Pancreatic adenocarcinoma does not express CD117/KIT as assessed using the primary immunohistochemical antibody usually used in our laboratory for CD117/KIT detection. The variation in reported incidence of CD117/KIT expression in pancreatic adenocarcinoma is because of methodological differences in immunohistochemical technique. Ideally, immunohistochemical studies of this molecule should be combined with mutational status testing of the c-kit gene.
authors.affiliation: Department of Cellular Pathology, Southampton General Hospital, Southampton, UK. adrian.bateman@suht.swest.nhs.uk
authors.forename: Adrian C
authors.initials: AC
authors.lastname: Bateman
authors.forename: Mary
authors.initials: M
authors.lastname: Judd
authors.forename: Dejan
authors.initials: D
authors.lastname: Radenkovic
authors.forename: Colin D
authors.initials: CD
authors.lastname: Johnson
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry*; D000918:Antibody Specificity; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004848:Epithelium / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D008407:Mast Cells / Q000737:chemistry; D010190:Pancreatic Neoplasms / Q000737:chemistry*; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D011786:Quality Control
chemical_list: D019009:Proto-Oncogene Proteins c-kit