Urinary Pyridinoline and Deoxypyridinoline as Potential Markers of Bone Metastasis in Patients with Prostate Cancer

Abstract
The levels of probable markers of bony metastatic disease were measured to evaluate their efficacy as predictors of disease and therapeutic outcome. Urinary pyridinoline, urinary deoxypyridinoline, serum alkaline phosphatase and serum osteocalcin were measured in patients with benign prostatic hyperplasia, clinically localized prostate cancer and prostate cancer with bone metastases. Also, urinary pyridinoline and deoxypyridinoline were compared in 2 groups of patients with metastatic prostate cancer of the bone who demonstrated progression or positive response to treatment. Urinary pyridinoline and deoxypyridinoline were determined by high performance liquid chromatography and were normalized to urinary creatinine. Levels of pyridinoline and deoxypyridinoline in urine, and the level of alkaline phosphatase in serum from patients with bone metastatic prostate cancer were significantly greater than levels in patients with benign prostatic hyperplasia or localized prostate cancer. Serum osteocalcin levels failed to separate the 3 groups. Serial measurement of urinary pyridinoline and deoxypyridinoline was correlated with a positive response to treatment (decreased) and with clinical progression of disease (increased) before detection of new bone lesions by bone scintigraphy. Measurement of urinary pyridinoline and deoxypyridinoline may provide a useful marker of prostate cancer metastatic to bone and may be useful in monitoring the response to treatment.