title: Post-adjuvant chemotherapy CA19-9 levels predict prognosis in patients with pancreatic ductal adenocarcinoma: A retrospective cohort study.
abstract: BACKGROUND
  Carbohydrate antigen 19-9 (CA19-9) is a widely used tumor marker for pancreatic ductal adenocarcinoma (PDAC). In addition, several studies have reported the utility of both pre- and postoperative CA19-9 levels as prognostic factors in resectable PDAC. However, little is known about the implications of post-adjuvant chemotherapy (AC) CA19-9 levels. The purpose of this study was to examine the utility of the post-AC CA19-9 level as a prognostic marker for relapse-free survival (RFS) in resectable PDAC.
  
  
  METHODS
  A total of 119 patients who completed AC were analyzed (normal post-AC CA19-9, n = 79; high post-AC CA19-9, n = 40). The upper limit of the normal (ULN) serum level of CA19-9 was 37 U/mL.
  
  
  RESULTS
  Median RFS was significantly shorter for patients with high post-AC CA19-9 levels than for those with normal post-AC CA19-9 (10.4 months vs. 29.6 months, respectively; p < 0.001). After adjustment, high post-AC CA19-9 level was an independent predictive factor for short RFS (hazard ratio for RFS, 2.72). Median overall survival was significantly shorter in patients with high post-AC CA19-9 levels than in those with normal postoperative CA19-9 levels (24.7 months vs. 92.1 months, respectively; p < 0.001). The optimal cutoff value of post-AC CA19-9 levels for prediction of early recurrence was >1.5 × UNL (55.5 U/mL), with a 74.2% positive predictive value.
  
  
  CONCLUSIONS
  The present results show that high post-AC CA19-9 level is an independent prognostic factor for short RFS in patients with resected PDAC. In addition, it may be useful for predicting early recurrence.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan. Electronic address: hiroshi.imaoka.md@aichi-cc.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imaoka
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Senda
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Natsume
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Mizuno
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Hijioka
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hieda
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tajika
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
mesh_terms: D000368:Aged; D018395:CA-19-9 Antigen / Q000032:analysis*; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D018395:CA-19-9 Antigen
keywords: Adjuvant chemotherapy; Biomarker; CA19-9; Pancreatic ductal adenocarcinoma; Surgery; Tumor marker