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.
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).