Cyclooxygenase-2 expression is associated with increased size in human sporadic colorectal adenomas.
BACKGROUND
Cyclooxygenase-2 (COX-2) has been implicated in colorectal carcinogenesis but its role is not completely defined.


METHODS
The expression of COX-2 was evaluated in 68 paraffin-embedded sporadic colorectal adenomas by immunohistochemistry. Associations between COX-2 expression and the clinicopathological characteristics of the adenomas were studied by contingency tables and the Chi-square test.


RESULTS
Cytoplasmic staining for COX-2 protein was present in epithelial cells of 62 out of the 68 adenomas. COX-2 expression was not associated with age or gender. Furthermore, no significant correlations were found between the expression of the protein and histology (tubular vs tubulovillous), localization (proximal vs distal) or morphology (sessil vs pedunculated) of the adenomas. Both stromal and epithelial COX-2 expressions were higher in larger (>4 mm) compared with smaller (< or =4 mm) adenomas (p =0. 037 and p=0. 024).


CONCLUSIONS
These data support the hypothesis that the expression of COX-2 may occur as a general phenomenon in colorectal adenomas. A size-dependent increase of COX-2 expression might be involved in colorectal carcinogenesis.
Pisano
Carmela
C
Medical Oncology B, National Cancer Institute, via Mariano Semmola, 80131, Naples, Italy. carmen_pisano@libero.it
Ottaiano
Alessandro
A
Tatangelo
Fabiana
F
Di Bonito
Maurizio
M
Falanga
Marzia
M
Iaffaioli
Vincenzo Rosario
VR
Botti
Gerardo
G
Pignata
Sandro
S
Acquaviva
Angela Maria
AM
D000236:Adenoma / Q000201:enzymology* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology*; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D016612:Paraffin Embedding; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*
D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases