Correlation of COX-2 Expression in Stromal Cells with High Stage, High Grade, and Poor Prognosis in Urothelial Carcinoma of Upper Urinary Tracts

Abstract

To investigate COX-2 expression in carcinoma and stromal cells in patients with urothelial carcinoma of upper urinary tracts (UCUUT) and determine whether expression patterns are associated with clinical characteristics and survival. We performed immunohistochemistry for COX-2 on paraffin-embedded tumors of UCUUT specimens from 79 patients. We evaluated the level of expression in carcinoma cells, presence of stromal cell expression, and infiltration of inflammatory cells. We observed strong and moderate expression of COX-2 in carcinoma cells in 19 (24.1%) and 46 (58.2%) cases, respectively. In 36 (45.6%) cases COX-2 expression was present in stromal cells. The level of COX-2 expression in carcinoma cells was not correlated with pathological stage (P = 0.22) or grade (P = 0.45). COX-2 expression in stromal cells was correlated with high stage (P <0.0001) and high grade (P <0.0001). The patient's survival was reduced if the tumor revealed strong or moderate expression of COX-2 in carcinoma cells (P = 0.03), the presence of COX-2 expression in stromal cells (P <0.0001), and infiltrating inflammatory cells (P = 0.0001), by log-rank test. Prognosis was poor if the tumor was positive for both COX-2 expression in stromal cells and inflammatory cell infiltrate (P <0.0001). COX-2 expression in stromal cells shows greater correlation with high stage and high grade than COX-2 expression in carcinoma cells. Stromal COX-2 expression may be used as a marker of invasiveness and poor prognosis for patients with UCUUT.