Expression of stem cell marker CD44 in prostate cancer biopsies predicts cancer grade in radical prostatectomy specimens.

Cancer stem cells play an important role in development and progression of many cancer types including prostate adenocarcinoma. We used a stem cell marker CD44 to evaluate the prevalence of prostate cancer stem cells in prostate biopsies and in matched radical prostatectomy specimens. We tested both types of specimen for the existence of a correlation between the immunohistochemical expression of CD44 and Gleason grade, pathological stage (pT) according to TNM, patient age and preoperative plasma PSA levels in 52 patients. We found a positive correlation between the expression of CD44 in cancer cells from prostate biopsies and in matched radical prostatectomy specimens. We also observed that higher level of CD44 expression in cancer cells correlated with lower Gleason score, both in prostate biopsies and in radical prostatectomies. To the best of our knowledge we showed for the first time, that the level of CD44 expression in prostate biopsies correlates with that observed in matched radical prostatectomy specimens. Since the level of CD44 expression was shown to predict a response to anti cancer therapy in several types of human tumors, CD44 assessment might support a clinical decision making process in prostate cancer patients.