Evaluation of PSA, free PSA, PSMA, and total and bone alkaline phosphatase levels compared to bone scans in the management of patients with metastatic prostate cancer.
BACKGROUND
Metastatic prostate cancer clinical evaluation is difficult. A revaluation of new prostate markers with regard to bone scans was performed.


METHODS
Serial markers, including bone alkaline phosphatase (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 possible 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 were 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 demonstrated that BAP and TAP had a significant discriminating ability for positive and negative bone scans (> .78), compared to PSMA, PSA, and fPSA. However, percent BAP and TAP only correlated with BSR at a level above six lesions. As the lesions detected by BSR increased, the correlation increased.


CONCLUSIONS
BAP is a valuable marker for clinical response evaluations to use in the serial follow-up of patients with metastatic 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).
Murphy
G P
GP
Cancer Research Division, Pacific Northwest Cancer Foundation, Northwest Hospital, Seattle, Washington 98125, USA.
Troychak
M J
MJ
Cobb
O E
OE
Bowes
V A
VA
Kenny
R J
RJ
Barren
R J
RJ
Kenny
G M
GM
Ragde
H
H
Holmes
E H
EH
Wolfert
R L
RL
D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000032:analysis* / Q000097:blood; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000097:blood; D000954:Antigens, Surface / Q000032:analysis* / Q000097:blood; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D001842:Bone and Bones / Q000737:chemistry* / Q000000981:diagnostic imaging / Q000201:enzymology; D005500:Follow-Up Studies; D043425:Glutamate Carboxypeptidase II; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000737:chemistry* / Q000473:pathology*; D012372:ROC Curve; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D000469:Alkaline Phosphatase; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II; D017430:Prostate-Specific Antigen