title: CA 19-9 as a predictor for response and survival in advanced pancreatic cancer patients treated with chemoradiotherapy.
abstract: OBJECTIVE
  To investigate the significance of carbohydrate antigen 19-9 (CA 19-9) levels for predicting response and survival in pancreatic cancer (PC) treated with concurrent chemoradiotherapy.
  
  
  METHODS
  We retrospectively reviewed data from 69 patients with PC between 1999 and 2005. All patients had elevated CA 19-9 levels before treatment. CA 19-9 levels (pre- and posttreatment CA 19-9) and their decline were analyzed for radiologic response and overall survival.
  
  
  RESULTS
  Seventeen patients (25%) had a 50% or greater reduction in tumor size within 3 months of chemoradiotherapy (1 complete response, 16 partial responses). CA 19-9 decline was significantly correlated with radiologic response (p = 0.03). The median survival time (MST) was 12 months (range, 4-48 months), and 1-year survival rate was 44%. Pretreatment CA 19-9 > 1,200 U/mL (MST, 13 vs. 8 months; p = 0.002), posttreatment CA 19-9 >100 U/mL (MST, 17 vs. 10 months; p = 0.0003), and CA 19-9 decline <or=40% (MST, 13 vs. 10 months; p = 0.005) were the strongest and most unfavorable prognostic factors. In addition, patients with multiple unfavorable CA 19-9 levels had significantly worse outcomes than those without.
  
  
  CONCLUSIONS
  CA 19-9 decline shows a correlation with radiologic response. The combination of pretreatment CA 19-9 >1,200 U/mL, posttreatment CA 19-9 >100 U/mL, and CA 19-9 decline <or=40% may possibly serve as a surrogate marker for poor survival in advanced PC receiving chemoradiotherapy.
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Woong Sub
authors.initials: WS
authors.lastname: Koom
authors.forename: Jinsil
authors.initials: J
authors.lastname: Seong
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.forename: Hae Ok
authors.initials: HO
authors.lastname: Pyun
authors.forename: Si Young
authors.initials: SY
authors.lastname: Song