Prognostic value of cyclooxygenase-2 expression in squamous cell carcinoma of the bladder

Inflammation is associated with the pathogenesis of carcinoma, including squamous cell carcinoma of the bladder. Cyclooxygenase-2 is an enzyme that is induced at inflammation sites. We assessed the expression pattern of cyclooxygenase-2 in patients with squamous cell carcinoma of the bladder and determined whether cyclooxygenase-2 expression is associated with clinical outcomes after radical cystectomy.

Immunohistochemical staining for cyclooxygenase-2 was done on archival bladder specimens from 152 patients treated with radical cystectomy for squamous cell carcinoma on the Autostainer (DakoCytomation, Carpinteria, California). Bright field microscopy imaging coupled with advanced color detection software was used. Cyclooxygenase-2 was defined as over expressed when greater than 20% cells were positive. We assessed the relationship of cyclooxygenase-2 expression with pathological parameters and clinical outcome.

The study included 99 male and 53 female patients with a mean age of 52 years who had squamous cell carcinoma, including 80.9% with bilharziasis. Presenting stage was T2 or greater and presenting grade was GII or less in 93.4% of patients. Median followup was 63.2 months. Cyclooxygenase-2 was over expressed in 74 cystectomy specimens (48.7%) and associated with higher pathological stage (p=0.003) and grade (p=0.049). On multivariate Cox proportional hazards regression analysis cyclooxygenase-2 over expression was associated with disease recurrence (p=0.031) and bladder cancer specific mortality (p=0.046).

Cyclooxygenase-2 over expression is associated with pathological stage, grade and worse outcomes after radical cystectomy, suggesting a role in bladder squamous cell carcinoma progression. Our findings support the need for further evaluation of cyclooxygenase-2 and inflammatory signaling pathways, and cyclooxygenase-2 targeted prevention or therapy in patients with bladder squamous cell carcinoma.