Expression of cyclooxygenase-2 protein in colorectal carcinomas.
BACKGROUND
Overexpression of cyclooxygenase-2 (COX-2) has been demonstrated in various human cancers, including colorectal cancer. Thus, overexpression of COX-2 may be involved in the growth and progression of cancer, and this may have prognostic significance.


OBJECTIVE
The aim of our study is to evaluate the expression of COX-2 in colorectal cancer tissue, and to examine the relationship of its expression to various clinicopathological parameters and patient survival.


METHODS
Formalin-fixed, paraffin-embedded tissue blocks were obtained from 60 patients who underwent surgery for colorectal carcinoma in 1995 at the Chonnam National University Hospital in Gwangju, Korea. We have used an immunohistochemical technique to localize COX-2 in colorectal carcinoma tissues.


RESULTS
Immunohistochemical staining of the colorectal cancer specimens demonstrated that COX-2 expression was localized to the carcinoma cells and was not detectable in the stromal compartment of the cancers. The COX-2 immunostaining pattern was predominantly homogenous, and perinuclear cytoplasmic within the tumors. Normal colonic epithelium adjacent to the tumor showed no staining for COX-2. The COX-2 protein was detected in 70% (42/60) of colorectal carcinoma tissues. However, no significant correlation was found between COX-2 expression and various clinicopathological parameters, including histologic grade, tumor size, depth of invasion, lymph node metastasis, distant metastasis, or stage. Furthermore, COX-2 expression did not correlate with patient survival (p = 0.401).


CONCLUSIONS
These results suggest that COX-2 expression may play an important role in the evolution of colon carcinogenesis. However, further studies are needed to determine the prognostic relevance of COX-2.
Joo
Young-Eun
YE
Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
Kim
Hyun-Soo
HS
Min
Sang-Woon
SW
Lee
Wan-Sik
WS
Park
Chang-Hwan
CH
Park
Chang-Soo
CS
Choi
Sung-Kyu
SK
Rew
Jong-Sun
JS
Kim
Sei-Jong
SJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D051546:Cyclooxygenase 2; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000096:biosynthesis*; D016019:Survival Analysis
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases