The Correlation of CD24 Expression with Tumor Stage and Grade in Urothelial Carcinomas of the Urinary Bladder

Abstract

Objective: Initially, CD24 was idendified as a B cell marker, in addition to a role of CD24 for the intracellular signaling, and it is also participates in the regulation of cell to cell and cell to matrix interactions. CD24 has been implicated in the progression of several types of cancer and has been identified as a prognostic factor in the last 10 years. We focused our attention on possible associations between CD24 expression and stage-grade of tumors in bladder urothelial carcinoma as important morphologic-prognostic paramaters. Methods: A total of 79 patients with bladder urothelial carcinomas were included in this study and these 79 patients underwent transurothelial resection biopsy at the Istanbul Education and research Hospital between 2005-2008. Hematoxylin-eosin stained sections from each case were reevaluated histopathologically according to the WHO-2004 grading system. The TNM system was used for pathologic staging. Selected slides were also studied by immunohistochemistry and a semiquantitative scoring for CD24 expression based on the percentage of positive cells was performed. Results: We found that CD24 expression was associated with invasive (pT1-2) and noninvasive (pTa) tumors. Normal urothelial epithelium and the adjacent non neoplastic urothelium in cancer specimens demostrated weak immunreactivity for CD24 and well-confined localization in the apical cytoplasm or apical membranes (Score 0-1). The most distinctive feature of CD24 expression was that the invasive cancer cells lost the apical polarity of CD24. The invasive cancer cells showed a nonpolarized cytoplasmic staining for CD24. The stage pTa tumor cells displayed weak staining in CD24 expression and most staining showed on apical localization. Conclusion: This study provides the basis of future investigations of CD24 as a potential serum marker or target of antibody-based therapeutics in bladder urothelial carcinoma.