title: ATP assay-guided chemosensitivity testing for gemcitabine with biopsy specimens obtained from unresectable pancreatic cancer using endoscopic ultrasonography-guided fine-needle aspiration.
abstract: OBJECTIVE
  This study evaluates the feasibility of chemosensitivity testing by use of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) samples and determines the optimum cut-off value for gemcitabine.
  
  
  METHODS
  Thirty-four consecutive patients with unresectable pancreatic cancer were enrolled. Chemosensitivity (treated/control ratio: T/C ratio) was calculated as the quantity of adenosine triphosphate for a tumor treated with gemcitabine as a percentage of that for the control. To identify the cut-off value sufficient to predict 180 days of progression-free survival (PFS), the receiver operating characteristic curve and the corresponding area under the curve (AUC) were calculated.
  
  
  RESULTS
  The success of this assay was 88.2% (30/34); therefore, 30 patients were assessable and included in the population of analyzable patients.. The response was 6.7%. Median PFS was 96 days and median overall survival was 241 days, respectively. The cut-off value was determined as 74% (AUC, 0.745; p = 0.053; 95% CI 0.485-1.005). According to this cut-off value, we predicted 180 days PFS with a sensitivity and specificity of 71.4 and 91.3%, respectively. When patients were divided into two groups at T/C ratio 74%, a significant difference was found in PFS (median 77 vs. 205 days, p = 0.0036). Moreover, T/C ratio < 74% and decrease of CA19-9 were significant and independent prognostic factors by multivariate analysis.
  
  
  CONCLUSIONS
  Chemosensitivity testing by use of EUS-FNA samples in patients with unresectable pancreatic cancer is feasible. This definition emphasizes the possibility of selecting patients for whom favorable results from gemcitabine treatment can be expected.
authors.affiliation: Department of Gastroenterology and Rheumatology, Fukushima Medical University, School of Medicine, 1 Hikarigaoka, Fukushima, 960-1295, Japan. wakachan@fmu.ac.jp
authors.forename: Takeru
authors.initials: T
authors.lastname: Wakatsuki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Irisawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Terashima
authors.forename: Goro
authors.initials: G
authors.lastname: Shibukawa
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Takagi
authors.forename: Hidemichi
authors.initials: H
authors.lastname: Imamura
authors.forename: Yuta
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Ai
authors.initials: A
authors.lastname: Sato
authors.forename: Masaki
authors.initials: M
authors.lastname: Sato
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Ikeda
authors.forename: Rei
authors.initials: R
authors.lastname: Suzuki
authors.forename: Takuto
authors.initials: T
authors.lastname: Hikichi
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Obara
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ohira
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D044963:Biopsy, Fine-Needle / Q000379:methods; D002470:Cell Survival; D002478:Cells, Cultured; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018572:Disease-Free Survival; D019160:Endosonography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000628:therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000255:Adenosine Triphosphate; D000093542:Gemcitabine