title: Preoperative carcinoembryonic antigen level as an independent prognostic factor in colorectal cancer: Taiwan experience.
abstract: BACKGROUND
  Preoperative carcinoembryonic antigen (CEA) level is considered as a factor predictive of survival in colorectal cancer patients. Patients with normal (<5 ng/ml) or lower preoperative CEA levels were reported to have significantly longer survival. This study was carried out in an effort to evaluate the prognostic significance of preoperative CEA levels of patients with colorectal cancer in Taiwan.
  
  
  METHODS
  Between 1990 and 1994, 218 patients with histologically confirmed colorectal cancers were evaluated retrospectively at the Veterans General Hospital-Taipei. All the patients had undergone potentially curative surgery. Patients with metastatic diseases were not included. 5-Fluorouracil-based adjuvant chemotherapy was administered if the patients had Dukes' C disease. Reference to the Dukes' classification was according to the classical criteria described in 1932 for carcinoma of the rectum and adapted for use in colonic tumors. Data on gender, age, degree of tumor differentiation, location of the tumor, tumor size, lymph node metastasis, penetration of the bowel wall and preoperative CEA levels were analyzed to determine their association with survival. Blood samples for CEA measurement were taken a few days before operation and were analyzed using the radioimmunoassay method. Multivariate analysis by Cox's proportional hazards regression model was performed to determine the most important predictors of survival among all of the possible variables.
  
  
  RESULTS
  By univariate analysis, the size of the tumor (p = 0.012), lymph node metastases (p = 0.007), penetration of the bowel wall (p < 0.001) and preoperative CEA levels (p < 0.001) were found to be significant prognostic factors, while gender, age, degree of tumor differentiation and location of the tumor were not significant. By multivariate Cox analysis, lymph node metastases (p = 0.003), penetration of the bowel wall (p = 0.0001) and preoperative CEA levels (p = 0.0001) were found to be independent prognostic factors in colorectal cancer patients.
  
  
  CONCLUSIONS
  The data from our study indicate that in addition to lymph node metastases and penetration of the bowel wall, the preoperative CEA levels are also an independent prognostic factor in non-metastatic colorectal cancer patients after curative surgery. This could serve as an appropriate modification to the initial Dukes' scheme in colorectal cancer.
authors.affiliation: Department of Medicine, Veterans General Hospital-Taipei and National Yang-Ming University School of Medicine, Taiwan.
authors.forename: W S
authors.initials: WS
authors.lastname: Wang
authors.forename: J K
authors.initials: JK
authors.lastname: Lin
authors.forename: T J
authors.initials: TJ
authors.lastname: Chiou
authors.forename: J H
authors.initials: JH
authors.lastname: Liu
authors.forename: F S
authors.initials: FS
authors.lastname: Fan
authors.forename: C C
authors.initials: CC
authors.lastname: Yen
authors.forename: T C
authors.initials: TC
authors.lastname: Lin
authors.forename: J K
authors.initials: JK
authors.lastname: Jiang
authors.forename: S H
authors.initials: SH
authors.lastname: Yang
authors.forename: H S
authors.initials: HS
authors.lastname: Wang
authors.forename: P M
authors.initials: PM
authors.lastname: Chen
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology / Q000601:surgery; D000367:Age Factors; D000704:Analysis of Variance; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D002272:Carcinoembryonic Antigen / Q000097:blood*; D017024:Chemotherapy, Adjuvant; D003106:Colon / Q000473:pathology; D003110:Colonic Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D005544:Forecasting; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D012007:Rectum / Q000473:pathology; D012189:Retrospective Studies; D012737:Sex Factors; D015996:Survival Rate; D013624:Taiwan
chemical_list: D000964:Antimetabolites, Antineoplastic; D002272:Carcinoembryonic Antigen; D005472:Fluorouracil