Ezrin expression in prostate cancer and benign prostatic tissue.
BACKGROUND
The membrane-linking protein ezrin is highly expressed in several types of human cancers and correlations between its immunoreactivity and histopathological data as well as patient outcome have previously been shown. However, such studies have not yet been done on human prostate cancer. This study assesses ezrin protein expression in a series of clinical specimens.


METHODS
Immunohistochemical analysis was used to characterize patterns of ezrin expression in prostatic carcinoma and benign epithelium in 103 radical prostatectomy specimens. Ezrin immunoreactivity (IR) was scored 0 to 3 (absent, weak, moderate or strong staining). Agreement between three independent observers was calculated.


RESULTS
Ezrin IR in prostate cancers was moderate or strong in 70% of specimens while negative or only weakly positive in benign epithelium. Interobserver agreement of IR score was substantial (mean weighted kappa 0.70, range 0.67-0.73). Ezrin expression correlated with Gleason score (p=0.016) and seminal vesicle invasion (p=0.006) but not with extraprostatic extension or margin status. No correlation with biochemical recurrence after prostatectomy was found (p=0.19). Urothelial and squamous metaplasia invariably showed moderate or strong ezrin expression. Epithelium of seminal vesicles and ejaculatory ducts was always intensely positive.


CONCLUSIONS
Ezrin was expressed in the majority of prostate cancers and correlated with adverse prognostic factors. Interestingly, high levels of ezrin IR were observed in benign metaplastic epithelium and in seminal vesicles.
Valdman
Alexander
A
Department of Surgical Science, Section of Urology, Karolinska Institute, Stockholm, Sweden.
Fang
Xiaolei
X
Pang
See-Tong
ST
Nilsson
Bo
B
Ekman
Peter
P
Egevad
Lars
L
D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D003598:Cytoskeletal Proteins; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010750:Phosphoproteins / Q000378:metabolism*; D011467:Prostate / Q000166:cytology / Q000378:metabolism*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D013223:Statistics as Topic; D000099149:Ezrin
D014408:Biomarkers, Tumor; D003598:Cytoskeletal Proteins; D010750:Phosphoproteins; D000099149:Ezrin