title: Serum CA 19-9 response to neoadjuvant therapy is associated with outcome in pancreatic adenocarcinoma.
abstract: BACKGROUND
  Baseline carbohydrate antigen 19-9 (CA 19-9) is a useful prognostic marker in pancreatic ductal adenocarcinoma (PDA); however, data on the significance of a change in CA 19-9 following neoadjuvant therapy are lacking.
  
  
  METHODS
  All patients receiving neoadjuvant therapy for PDA from July 2010 to February 2013 were retrospectively reviewed. Resection rate, R0 resection rate, need for venous resection, and overall survival were correlated to CA 19-9 response. Fisher's exact test, Kaplan-Meier survival analysis, and multivariate analysis using Cox regression were used.
  
  
  RESULTS
  A total of 78 patients were studied (21 patients with resectable disease, 40 borderline resectable, and 17 with locally advanced disease). A variety of chemotherapies ± radiation were utilized during the study period. Overall, 56 patients (72 %) had a decrease in CA 19-9 of >50 % with neoadjuvant treatment. In borderline resectable patients, CA 19-9 response of >50 % predicted R0 resection (odds ratio 4.2; p = 0.05). In borderline resectable patients who had an increase in CA 19-9, none of five (0 %) underwent R0 resection compared with 80 % of the remaining cohort (p = 0.001). The complete pathologic response rate was 29 % in patients who had a CA 19-9 response of >90 % versus 0 % in the remaining patients (p < 0.001). A CA 19-9 response of >50 % resulted in improved overall survival (28.0 vs. 11.1 months; p < 0.0001) and was an independent predictor of survival (hazard ratio 0.26; 95 % CI 0.13-0.55; p < 0.0001).
  
  
  CONCLUSIONS
  CA 19-9 response to neoadjuvant therapy is associated with R0 resection rate, histopathologic response, and survival. Incorporation of this easily obtainable biomarker into future clinical trials may facilitate more rapid evaluation of novel regimens.
authors.affiliation: Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Boone
authors.forename: Jennifer
authors.initials: J
authors.lastname: Steve
authors.forename: Mazen S
authors.initials: MS
authors.lastname: Zenati
authors.forename: Melissa E
authors.initials: ME
authors.lastname: Hogg
authors.forename: Aatur D
authors.initials: AD
authors.lastname: Singhi
authors.forename: David L
authors.initials: DL
authors.lastname: Bartlett
authors.forename: Amer H
authors.initials: AH
authors.lastname: Zureikat
authors.forename: Nathan
authors.initials: N
authors.lastname: Bahary
authors.forename: Herbert J
authors.initials: HJ
authors.lastname: Zeh
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen