COMPARISON OF SERUM PSMA, PSA LEVELS WITH RESULTS OF CYTOGEN-356 PROSTASCINT(R) SCANNING IN PROSTATIC-CANCER PATIENTS

BACKGROUND. Stored serum from clinical trial cases undergoing ProstaSc int(R) (CYT-356) scanning were available for Prostate Specific Membran e Antigen (PSMA) assay. Prostate Specific Antigen (PSA) levels had alr eady been determined. This provided an opportunity to see what correla tions existed between the serum markers and the ProstaScint(R) scan. A group of patients had the studies preprostatectomy, whereas another g roup had the studies postprostatectomy. METHODS. The scan results, ser um PSA, serum PSMA, and clinical data were separately analyzed. PSMA s erum levels were determined by Western blot. RESULTS. Preoperatively, radical prostatectomy patients showed a correlation between serum PSA or PSMA levels and the ProstaScint(R) scan in the total group (n = 86) , or in an untreated group (n = 38). Preoperatively, PSMA correlated w ith the pathological stage, whereas PSA correlated with the scan. Post operatively, only PSMA serum levels correlated with the scan in an unt reated group (n = 40). CONCLUSIONS. Preoperatively or postoperatively, Western blot PSMA serum levels predict the stage of disease or local, regional, or distant metastases, as shown by ProstaScint(R) scan. Bot h the scan and the serum tests provide prognostic information and eval uate the extent of disease to a more significant degree than previousl y possible. (C) 1997 Wiley-Liss, Inc.