Prostate stem cell antigen expression is associated with gleason score, seminal vesicle invasion and capsular invasion in prostate cancer.
OBJECTIVE
Few successful therapeutic options exist for men who present with metastatic prostate cancer (CaP) or for the 30% with recurrence. The development and characterization of molecular markers are vital to the development of prognostic and therapeutic modalities in CaP. We investigated the expression and potential clinical usefulness of prostate stem cell antigen (PSCA) in CaP using tissue microarrays.


METHODS
Immunohistochemical analysis using a PSCA monoclonal antibody was performed on tissue microarrays constructed from paraffin embedded specimens from 246 patients who underwent radical retropubic prostatectomy. PSCA staining was correlated with established prognostic factors, such as Gleason score, prostate specific antigen (PSA), and seminal vesicle invasion. In addition, recurrence-free survival was analyzed.


RESULTS
A high PSCA intensity of 3 was associated with adverse prognostic features, such as Gleason score 7 and above (p = 0.001), seminal vesicle invasion (p = 0.005) and capsular involvement (p = 0.033). On univariate analysis tumors with a PSCA intensity of 3 carried an increased risk of PSA recurrence (p = 0.031, HR 1.77, 95% CI 1.05 to 2.96). However, after adjusting for these variables a PSCA intensity of 3 was no longer an independent predictor of PSA recurrence.


CONCLUSIONS
We found that high PSCA intensity is significantly associated with adverse prognostic features such as high Gleason score and extra-organ disease. The results of this study suggest that PSCA is a promising tumor marker for the selection of patients at high risk but additional studies are necessary to assess the usefulness of PSCA in patient biopsies.
Han
Ken-Ryu
KR
Department of Urology, University of California-Los Angeles David Geffen School of Medicine, Los Angeles, California 90095-1738, USA.
Seligson
David B
DB
Liu
Xueli
X
Horvath
Steve
S
Shintaku
Peter I
PI
Thomas
George V
GV
Said
Jonathan W
JW
Reiter
Robert E
RE
D000368:Aged; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D005500:Follow-Up Studies; D058851:GPI-Linked Proteins; D005834:Genital Neoplasms, Male / Q000473:pathology*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000473:pathology*; D012189:Retrospective Studies; D012669:Seminal Vesicles
D000951:Antigens, Neoplasm; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C110843:PSCA protein, human