Cyclooxygenase-2 expression: a significant prognostic indicator for patients with colorectal cancer.
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.
Soumaoro
Labile Togba
LT
Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Uetake
Hiroyuki
H
Higuchi
Tetsuro
T
Takagi
Yoko
Y
Enomoto
Masayuki
M
Sugihara
Kenichi
K
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
D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases