title: Staining for p53 and Ki-67 increases the sensitivity of EUS-FNA to detect pancreatic malignancy.
abstract: OBJECTIVE
  To investigate whether tumor marker staining can improve the sensitivity of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to diagnose pancreatic malignancy.
  
  
  METHODS
  Patients who underwent EUS-FNA were retrospectively identified. Each EUS-FNA specimen was evaluated by routine cytology and stained for tumor markers p53, Ki-67, carcinoembryonic antigen (CEA) and CA19-9. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and positive and negative likelihood ratios (PLR and NLR) were calculated in order to evaluate the performance of each test to detect malignancy.
  
  
  RESULTS
  Sixty-one specimens had complete sets of stains, yielding 49 and 12 specimens from pancreatic adenocarcinomas and benign pancreatic lesions due to pancreatitis, respectively. Cytology alone had sensitivity and specificity of 41% and 100% to detect malignancy, respectively. In 46% of the specimens, routine cytology alone was deemed indeterminate. The addition of either p53 or Ki-67 increased the sensitivity to 51% and 53%, respectively, with perfect specificity, PPV and PLR (100%, 100% and infinite). Both stains in combination increased the sensitivity to 57%. While additional staining with CEA and CA19-9 further increased the sensitivity to 86%, the specificity, PPV and PLR were significantly reduced (at minimum 42%, 84% and 1, respectively). Markers in all combinations performed poorly as a negative test (NPV 26% to 47%, and NLR 0.27 and 0.70).
  
  
  CONCLUSIONS
  Immunohistochemical staining for p53 and Ki-67 can improve the sensitivity of EUS-FNA to diagnose pancreatic adenocarcinoma.
authors.affiliation: Alexander W Jahng, Donna Varela, Sonya Reicher, David Chung, Rahul Chhablani, Anil Dev, Binh Pham, Jose Nieto, Viktor E Eysselein, Division of Gastroenterology, Harbor-UCLA Medical Center, Torrance, CA 90502, United States.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Jahng
authors.forename: Sonya
authors.initials: S
authors.lastname: Reicher
authors.forename: David
authors.initials: D
authors.lastname: Chung
authors.forename: Donna
authors.initials: D
authors.lastname: Varela
authors.forename: Rahul
authors.initials: R
authors.lastname: Chhablani
authors.forename: Anil
authors.initials: A
authors.lastname: Dev
authors.forename: Binh
authors.initials: B
authors.lastname: Pham
authors.forename: Jose
authors.initials: J
authors.lastname: Nieto
authors.forename: Rose J
authors.initials: RJ
authors.lastname: Venegas
authors.forename: Samuel W
authors.initials: SW
authors.lastname: French
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Stabile
authors.forename: Viktor E
authors.initials: VE
authors.lastname: Eysselein