PanCD44 Immunohistochemical Evaluation in Prostatectomies from Patients with Adenocarcinoma.

Introduction: CD44 has been proposed as a prognostic marker and a stem cell marker but studies in patients with prostate cancer have yielded inconsistent results.

Patients and Methods: Patients submitted to radical prostatectomy between 2008 and 2013 at a university hospital were followed with biannual serum PSA tests to determine the biochemical recurrence (BR). Archived paraffin blocks with neoplastic and nonneoplastic tissue were evaluated immunohistochemically for a panCD44 and MYC.

Results: Sixty-nine patients completed follow-up and were included. CD44 positivity was observed in inflammatory cells (42%), nonneoplastic epithelium (39.7%), and neoplastic tissue (12.3%). In nonneoplastic tissues staining was observed in basal and luminal cells with the morphology of terminally differentiated cells. In neoplastic tissues, CD44 negativity was correlated with higher Gleason scores (Rho = -0.204; p = 0.042) and higher preoperative serum PSA levels when evaluated continuously ( p = 0.029). CD44 expression was not associated with tumor stage ( p = 0.668), surgical margin status ( p = 0.471), or BR ( p = 0.346), nor was there any association between CD44 and MYC expression in neoplastic tissue ( p = 1.0).

Conclusion: In the bulk of cells, the minority of cancer stem cells would not be detected by immunohistochemistry using panCD44. As a prognostic marker, its expression was weakly correlated with Gleason score and preoperative PSA level, but not with surgical margin status, tumor stage, or BR.