Role of COX-2 in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis.
OBJECTIVE
Recent clinical epidemiological studies have demonstrated the preventive effect of non-steroidal anti-inflammatory drugs (NSAIDs) against colorectal cancer. The underlying mechanism might be the inhibition of rate-limiting enzyme cyclooxygenase-2 (COX-2) in metabolism of arachidonic acid. The role of COX-2 in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis still remain unclear. This study was to investigate the role of COX-2 expression in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis.


METHODS
A total of 139 colorectal cancers and 19 adenomas surgically treated in School of Oncology, Peking University, from January 1993 to September 2001 were retrospectively studied. COX-2 expression was detected with tissue microarray (TMA) and immunohistochemistry (IHC) procedure. The association between COX-2 expression and clinicopathological features and its influence on patients' prognosis were studied.


RESULTS
COX-2 expression was strong in colorectal cancer, moderate in adenoma and weak in normal mucosa, which demonstrated statistically significant difference (chi(2)=46.997, P<0.001). COX-2 expression had no association with clinicopathological features such as gross type, differentiation, invasion depth, vessel emboli and TNM staging. Cox proportional hazards modeling analysis and Log rank test revealed no prognostic role of COX-2 expression in colorectal cancer patients.


CONCLUSIONS
COX-2 may play an important role in the early stage of carcinogenesis, and its expression in colorectal cancer is not associated with clinicopathological features and patients' prognosis.
Wu
Ai-Wen
AW
Department of Surgery, Peking University, School of Oncology, Beijing Cancer Hospital, Beijing Institute of Cancer Research, China.
Gu
Jin
J
Ji
Jia-Fu
JF
Li
Zhen-Fu
ZF
Xu
Guang-Wei
GW
D000230:Adenocarcinoma / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D000236:Adenoma / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012189:Retrospective Studies
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases