Cyclooxygenase-2 expression in human colorectal cancer is unrelated to overall patient survival.
OBJECTIVE
Cyclooxygenase-2 (COX-2) expression in human colorectal cancer and adenoma tissue seems to be higher than in normal mucosa. However, data about the relation between COX-2 expression and patient survival are inconclusive as yet. Therefore, we studied COX-2 expression in surgery tissue and survival time in a cohort of 747 colorectal cancer patients.


METHODS
Surgical specimens of primary colorectal cancer from 747 individuals were immunostained for COX-2 and evaluated under a transmission light microscope. COX-2 expression was scored according to intensity and extent of staining, resulting in the COX-2 immunoreactivity score (IRS-COX2). All possible cutoff points for IRS-COX2 were analyzed for a relation between COX-2 expression and patient survival.


RESULTS
Both univariable and multivariable analysis have shown that the COX-2 expression in human tumor epithelial cells was unrelated to overall patient survival and to disease-free survival, irrespectively of the cutoff point for IRS-COX2. The survival rates for 1, 3, 5, and 10 years were 81.0%, 66.8%, 60.2%, and 49.8% (median: 117.3 months; 95% confidence interval, 102.3-132.0), respectively. In the multivariable analysis, only node and metastasis were significantly related to overall patient survival. Similar results were obtained when stage IV and rectal cancer patients were excluded from the analysis.


CONCLUSIONS
COX-2 expression in tumor epithelial cells does not seem to be related to survival of colorectal cancer patients. Besides COX-2, there are several targets, such as the peroxisome proliferator-activated receptors, that are involved in carcinogenesis and may be modulated by nonsteroidal anti-inflammatory drugs. Further studies are needed to determine their prognostic relevance.
Fux
Richard
R
Abteilung Klinische Pharmakologie, Institut für Pharmakologie und Toxikologie, Universitätsklinikum Tübingen, Tübingen, Germany.
Schwab
Matthias
M
Thon
Klaus-Peter
KP
Gleiter
Christoph H
CH
Fritz
Peter
P
D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016019:Survival Analysis