EVALUATION OF PSA, FREE PSA, PSMA, AND TOTAL AND BONE ALKALINE-PHOSPHATASE LEVELS COMPARED TO BONE SCANS IN THE MANAGEMENT OF PATIENTS WITHMETASTATIC PROSTATE-CANCER

BACKGROUND. Metastatic prostate cancer clinical evaluation is difficul t. A revaluation of new prostate markers with regard to bone scans was performed. METHODS. Serial markers, including bone alkaline phosphata se (BAP), total alkaline phosphatase (TAP), prostate-specific antigen, total (PSA) and free (fPSA), and prostate-specific membrane antigen ( PSMA), were obtained in patients under evaluation and treatment for po ssible or known metastatic prostate cancer. These were correlated with bone scan results (BSR). RESULTS. Seventy patients were observed from mid-October 1996-January 1997, during which time 171 serum samples we re obtained and correlated with semiquantitative bone scan status. PSA and fPSA provided some correlation with BAP and BSR, but only at high levels (>16-50 ng/ml). Receiver-operating curve (ROC) analysis demons trated that BAP and TAP had a significant discriminating ability for p ositive and negative bone scans (>.78), compared to PSMA, PSA, and fPS A. However, percent BAP and TAP only correlated with BSR at a level ab ove six lesions. As the lesions detected by BSR increased, the correla tion increased. CONCLUSIONS. BAP is a valuable marker for clinical res ponse evaluations to use in the serial follow-up of patients with meta static prostate cancer, and correlates well with the bone scan as the number of lesions increase to >6. PSA or fPSA show comparable results, but only at high levels (>16-50 ng/ml). (C) 1997 Wiley-Liss, Inc.