Objectives: To improve the prediction of pathologic stage beyond that provided by Gleason score.
Methods: We investigated the tissue expression in prostate cancer of a relatively new marker, oncoantigen 519 (OA-519). Because Gleason score is one of the most powerful predictors in prostate cancer, we restricted our evaluation to 66 radical prostatectomy specimens of varying pathologic stages which were either Gleason score 6 or 7. Immunohistochemical staining of OA-519 was assessed with a combined staining score from 0 to 8, taking into account both the intensity and percentage of tissue staining. In addition, an intensity score was derived based on whether any intense staining was present in case.
Results: OA-519 staining of the primary prostate cancer was highly predictive in separating cases with organ-confined disease or capsular penetration versus cases with seminal vesicle invasion or lymph node metastases; Gleason score 6 or 7 was also predictive. In a logistic multivariate regression analysis, both OA-519 and Gleason score were strong independent predictors of pathologic stage (P = 0.0004).
Conclusions: OA-519 predicted pathologic stage well when analyzing primary prostate cancer in radical prostatectomy specimens and is presently being investigated on preoperative biopsy material to assess its ultimate clinical applicability. OA-519 has significant promise as a prognostic marker for prostate cancer and is one of the few markers that provides additional predictive information beyond that of the Gleason score.