Analysis of bone alkaline phosphatase as a marker for the diagnosis of osteoporosis in men under androgen ablation

• Published in: The International journal of biological markers 2003-10, Vol.18 (4), p.290-294
• Main Authors: MOROTE, J, TRILLA, E, ESQUENA, S, ABASCAL, J. M, SEGURA, R. M, CATALAN, R, ENCABO, G, REVENTOS, J
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alkaline Phosphatase - blood; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Biomarkers - blood; Bone and Bones - enzymology; Bone Density; Bone Diseases, Metabolic - blood; Fundamental and applied biological sciences. Psychology; Hip Fractures - epidemiology; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Osteoporosis - blood; Osteoporosis - diagnosis; Predictive Value of Tests; Prostatic Neoplasms - blood; Prostatic Neoplasms - surgery; Reproducibility of Results; Risk; Sensitivity and Specificity
• ISSN: 0393-6155; 1724-6008
• DOI: 10.1177/172460080301800407

The objective of this study was to evaluate the usefulness of serum determination of bone alkaline phosphatase (BAP) in the diagnosis of osteoporosis in men with prostate cancer under androgen ablation. Serum levels of BAP and bone mineral density (BMD) were assessed in 110 patients with non-metastatic, treated prostate cancer. Fifty-eight patients were under androgen deprivation during a period between two and 96 months and 52 had been submitted only to radical prostatectomy. Mean serum BAP was 11.8 ng/mL in patients with normal BMD, 16.7 ng/mL in patients with osteopenia (p. 0.058), and 19.3 ng/mL in patients with osteoporosis (p = 0.044). The correlation between serum BAP and BMD was significant (p. 0.006) but with an index of only 0.26. Receiver operating characteristic analysis for the diagnosis of osteoporosis showed an area under the curve of 0.608. None of the cutoff points that provided specificities of 75%, 90% and 95% gave significant distributions. The positive and negative predictive values as well as the odds ratios were not of any clinical usefulness. We conclude that serum BAP should not be considered a good marker for the diagnosis of osteoporosis in men with prostate cancer. Therefore, BAP serum determination cannot replace bone densitometry as a diagnostic tool.