Evaluation of COX-2 expression in renal cell carcinoma and its correlation with clinicopathological factors: a tissue microarray study

Objectives: This study, aimed to evaluate the expression of COX-2 in renal cell carcinoma, and correlate it with different patient clinicopathological data, emphasizing on the role of COX-2 as a prognostic factor for renal cell carcinoma and to decide which cases more likely benefit from the targeted therapy later on. Patients and Methods: The present series consisted of tissue samples obtained from 47 patients (30 patients were males and 17 were females). All the tumor samples were collected from the Pathology Department, Faculty of Medicine, Alexandria University during the period from July 2009 to November 2010. Archival paraffin-embedded renal cell carcinoma tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with COX-2 antibody. Marker expression was categorized for statistical analysis then correlated to clinicopathological variables. Results: The histological types was significantly associated with COX-2 expression, with higher expression being more common in papillary and chromophobe renal cell carcinoma, the majority of these two types were in score 1 and 2 while majority of clear cell renal cell carcinoma had score 0 and 1. Conclusion: The association of COX-2 marker was related to the histologic type of tumor; COX-2 expression study might provide prognostic information regarding tumor aggressiveness. These findings suggested a potential impact of COX-2 targeted therapy in the treatment of renal cell carcinoma with overexpressed COX-2 that needs further investigation.