Cyclooxygenase-2 expression: does it have a probable role in tumorigenesis mechanisms of renal cell carcinoma?
OBJECTIVE
The purpose of this study was to evaluate the correlation between the levels of cyclooxygenase-2 (COX-2) expression with clinicopathologic features and determine the impact on prognosis in patients with renal cell carcinoma (RCC).


METHODS
Expression of COX-2 was evaluated immunohistochemically in RCC tissues from 62 patients who underwent radical nephrectomy between 1996 and 2004. Percentage of COX-2 staining was scored as 0 (negative), 1 (1-24%), 2 (25-49%), 3 (50-74%), and 4 (75-100%). Immunohistochemical COX-2 staining score (ISS) was defined as summation of intensity and percentage of COX-2 staining.


RESULTS
Twenty-seven patients (43.5%) with a median follow-up of 47.8 (25-115) months stained positively for COX-2. COX-2 expression was positive in 37.1%, 50%, and 66.7% of patients with stages 1, 2, and 3, respectively (P = 0.46). Correlation between ISS and pathological stage was statistically significant (P = 0.005). Multivariate regression analysis revealed no clinicopathologic parameter as independent predictors of progression. Kaplan-Meier analysis revealed statistically significant different survival rates in tumor stage, grade, and ISS.


CONCLUSIONS
Although COX-2 expression is not an independent predictor of progression in patients with RCC, patients with higher ISS values have significantly shorter progression-free survival rates. These results might be important to the clinician because positive COX-2 expression of a certain RCC might necessitate early adjuvant systemic therapy to delay the progression of RCC. For this reason, there is a need for innovative, prospective, and randomized studies in patients with positive COX-2 expression that will display the impact of systemic therapies in these patients.
Sozen
Sinan
S
Department of Urology, Gazi University School of Medicine, Ankara 06500, Turkey.
Gurocak
Serhat
S
Erdem
Ozlem
O
Acar
Cenk
C
Kordan
Yakup
Y
Akyol
Gulen
G
Alkibay
Turgut
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis
D051546:Cyclooxygenase 2