title: S100P and XIAP expression in pancreatic ductal adenocarcinoma: potential novel biomarkers as a diagnostic adjunct to fine needle aspiration cytology.
abstract: OBJECTIVE
  The usefulness of 2 novel biomarkers in pancreatic surgical and cytological specimens that could reliably differentiate non-neoplastic pancreatic duct and benign gut epithelium from pancreatic ductal adenocarcinoma (PDA) was evaluated.
  
  
  METHODS
  A total of 14 pancreatic resection specimens (RSs), 23 endoscopic ultrasound-guided fine needle aspirations (EUS-FNAs) of PDA and 8 benign pancreatic EUS-FNAs were selected. Twelve of 14 RSs had corresponding EUS-FNAs with cell blocks (CBs). Non-neoplastic pancreatic tissue, including chronic pancreatitis, was evaluated in all RSs. Immunohistochemical stains for S100P and X-linked inhibitor of apoptosis protein (XIAP) were performed on tissue and CB sections. Staining intensity (0 no staining; 1+ weak; 2+ moderate; 3+ strong) and proportion of positive cells (less than 10% negative; 1+ 10-25%; 2+ 26-75%; 3+ greater than 75%) were assessed. Positive staining was defined as ≥10% cells with at least 1+ intensity.
  
  
  RESULTS
  The sensitivity and specificity of S100P and XIAP immunoreactivity for a diagnosis of PDA in RSs were both 100%. In contrast, the sensitivity and specificity in EUS-FNA CBs of S100P were 78.2 and 87.5% and of XIAP 82.6 and 50.0%, respectively. The combined sensitivity of S100P and XIAP was 100% in 12 RSs and 83.3% in the corresponding EUS-FNA CBs.
  
  
  CONCLUSIONS
  Two novel biomarkers have very high sensitivity and specificity in the diagnosis of PDA in RSs. S100P has slightly lower sensitivity and higher specificity of PDA than XIAP in EUS-FNA specimens. We recommend using both biomarkers as cytological diagnostic adjuncts, especially in difficult cases of well-differentiated PDA versus reactive ductal epithelium.
authors.affiliation: Department of Pathology, The Methodist Hospital, Houston, TX 77030, USA.
authors.forename: Ognjen
authors.initials: O
authors.lastname: Kosarac
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Takei
authors.forename: Qihui Jim
authors.initials: QJ
authors.lastname: Zhai
authors.forename: Mary R
authors.initials: MR
authors.lastname: Schwartz
authors.forename: Dina R
authors.initials: DR
authors.lastname: Mody
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D009363:Neoplasm Proteins; C103003:S100P protein, human; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human