title: Carbohydrate antigen 19-9 is a valuable prognostic factor in colorectal cancer patients with normal levels of carcinoembryonic antigen and may help predict lung metastasis.
abstract: OBJECTIVE
  We retrospectively analyzed preoperative levels of carbohydrate antigen (CA) 19-9 in colorectal cancer (CRC) patients to determine the prognostic value of CA19-9 in CRC patients with normal carcinoembryonic antigen (CEA) levels.
  
  
  METHODS
  A total of 639 patients who underwent curative surgery at Taipei Veterans General Hospital between 2002 and 2006 were enrolled. We excluded 254 patients (39.7 %) with high preoperative CEA levels and analyzed 385 patients with normal CEA levels. The measured endpoint was the postoperative disease-free survival (DFS). The prognostic value of CA19-9 was determined using log-rank test and Cox regression analysis.
  
  
  RESULTS
  High CA19-9 levels were significantly associated with advanced disease and were detected in 5.8 % of patients with stage I disease, 11.7 % of those with stage II disease, and 22.5 % of those with stage III disease (P < 0.001). The 5-year DFS in patients with normal CA19-9 levels was 82.0 %, which was significantly higher than that in patients with high CA19-9 levels (68 %; P < 0.001). In a multivariate analysis, the most important independent factor affecting the 5-year DFS was tumor-node-metastasis stage (95 % CI, 1.26-2.36; HR = 1.72). After stratification by other factors, high CA19-9 level remained an independent prognostic factor for patients with normal CEA levels. Patients with high CA19-9 levels also showed a higher incidence of lung metastasis (23.1 %) than those with normal CA19-9 levels (7.2 %).
  
  
  CONCLUSIONS
  CA19-9 may be a prognostic factor for CRC patients with normal CEA levels. An aggressive follow-up protocol for lung metastasis should be used for these patients.
authors.affiliation: Department of Clinical Pathology, Yang-Ming Campus, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Pei-Ching
authors.initials: PC
authors.lastname: Lin
authors.forename: Jen-Kou
authors.initials: JK
authors.lastname: Lin
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Lin
authors.forename: Huann-Sheng
authors.initials: HS
authors.lastname: Wang
authors.forename: Shung-Haur
authors.initials: SH
authors.lastname: Yang
authors.forename: Jeng-Kai
authors.initials: JK
authors.lastname: Jiang
authors.forename: Yuan-Tzu
authors.initials: YT
authors.lastname: Lan
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Lin
authors.forename: Anna Fen-Yau
authors.initials: AF
authors.lastname: Li
authors.forename: Wei-Shone
authors.initials: WS
authors.lastname: Chen
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary*; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen