title: Cyclooxygenase-2 expression: a significant prognostic indicator for patients with colorectal cancer.
abstract: OBJECTIVE
  Recent studies have shown that cyclooxygenase (Cox)-2 may be involved in colorectal carcinogenesis. We aimed to determine whether Cox-2 expression in itself can predict outcome of colorectal cancer patient after surgery. In addition, the expression of Cox-1 was also evaluated.
  
  
  METHODS
  Tissue samples of primary and secondary tumors from 288 patients undergoing surgical resections for colorectal adenocarcinoma were immunohistochemically examined for Cox-2 and Cox-1 expressions. The specimens were graded based on the intensity and extent of staining; then, the correlations between Cox-2 and Cox-1 expressions with clinicopathologic parameters and survival time were analyzed.
  
  
  RESULTS
  Expression of Cox-2 was positive in 70.8% of primary tumor, 92.0% of lymph node metastases, 100.0% of hepatic metastases, and was significantly associated with tumor size, depth of invasion, lymph node metastasis, vessels invasion, stage and recurrence. In contrast, Cox-1 was positive in 42.7% of primary tumor, 84.0% of lymph node metastases, 37.5% hepatic metastases, and was associated with only tumor size. Patients with Cox-2-positive tumors had a significant shorter survival time than those with negative tumors did (P = 0.0006 by log-rank test); and, in a multivariate analysis, Cox-2 was an independent prognostic factor (P = 0.0103; relative risk 4.114; 95% confidence interval, 1.397-12.120). Cox-1 status had no statistically effect on patient survival time.
  
  
  CONCLUSIONS
  Elevated Cox-2 expression, but not that of Cox-1, was significantly associated with reduced survival and recognized as an independent prognostic factor in our cohort of colorectal cancer patients.
authors.affiliation: Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Labile Togba
authors.initials: LT
authors.lastname: Soumaoro
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uetake
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Higuchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takagi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Enomoto
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000201:enzymology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015331:Cohort Studies; D003106:Colon / Q000378:metabolism; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000201:enzymology*; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D008113:Liver Neoplasms / Q000201:enzymology / Q000556:secondary; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000175:diagnosis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000201:enzymology; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000201:enzymology*; D012007:Rectum / Q000378:metabolism; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases