title: Serum CA 19-9 as a marker of resectability and survival in patients with potentially resectable pancreatic cancer treated with neoadjuvant chemoradiation.
abstract: OBJECTIVE
  The role of carbohydrate antigen (CA) 19-9 in the evaluation of patients with resectable pancreatic cancer treated with neoadjuvant therapy prior to planned surgical resection is unknown. We evaluated CA 19-9 as a marker of therapeutic response, completion of therapy, and survival in patients enrolled on two recently reported clinical trials.
  
  
  METHODS
  We analyzed patients with radiographically resectable adenocarcinoma of the head/uncinate process treated on two phase II trials of neoadjuvant chemoradiation. Patients without evidence of disease progression following chemoradiation underwent pancreaticoduodenectomy (PD). CA 19-9 was evaluated in patients with a normal bilirubin level.
  
  
  RESULTS
  We enrolled 174 patients, and 119 (68%) completed all therapy including PD. Pretreatment CA 19-9 <37 U/ml had a positive predictive value (PPV) for completing PD of 86% but a negative predictive value (NPV) of 33%. Among patients without evidence of disease at last follow-up, the highest pretreatment CA 19-9 was 1,125 U/ml. Restaging CA 19-9 <61 U/ml had a PPV of 93% and a NPV of 28% for completing PD among resectable patients. The area under the receiver-operating characteristics curve of pretreatment and restaging CA 19-9 levels for completing PD was 0.59 and 0.74, respectively. We identified no association between change in CA 19-9 and histopathologic response (P = 0.74).
  
  
  CONCLUSIONS
  Although the PPV of CA 19-9 for completing neoadjuvant therapy and undergoing PD was high, its clinical utility was compromised by a low NPV. Decision-making for patients with resectable PC should remain based on clinical assessment and radiographic staging.
authors.affiliation: Department of Surgery, The University of California, Orange, CA, USA. katzmh@uci.edu
authors.forename: Matthew H G
authors.initials: MH
authors.lastname: Katz
authors.forename: Gauri R
authors.initials: GR
authors.lastname: Varadhachary
authors.forename: Jason B
authors.initials: JB
authors.lastname: Fleming
authors.forename: Robert A
authors.initials: RA
authors.lastname: Wolff
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Lee
authors.forename: Peter W T
authors.initials: PW
authors.lastname: Pisters
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Vauthey
authors.forename: Eddie K
authors.initials: EK
authors.lastname: Abdalla
authors.forename: Charlotte C
authors.initials: CC
authors.lastname: Sun
authors.forename: Huamin
authors.initials: H
authors.lastname: Wang
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Crane
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Lee
authors.forename: Eric P
authors.initials: EP
authors.lastname: Tamm
authors.forename: James L
authors.initials: JL
authors.lastname: Abbruzzese
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Evans
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000401:mortality / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018395:CA-19-9 Antigen / Q000097:blood*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D016577:Pancreaticoduodenectomy; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D018395:CA-19-9 Antigen