Biochemical markers of bone turnover in patients with localized and metastasized prostate cancer.

OBJECTIVE: To evaluate and compare the value of several markers of bone turnover in different stages of prostate cancer, as bone metastases are a common feature in this disease, and for assessing bone metastases both bone formation and bone resorption markers are diagnostic. PATIENTS AND METHODS: The prospective study included 219 men, i.e. 129 undergoing radical retropubic prostatectomy (RRP) and 25 with bone metastases due to prostate cancer, and 65 with benign urological disorders who served as controls. Before any treatment the concentrations of alkaline phosphatase (ALP), osteocalcin, serum C-terminal telopeptide of type I collagen (S-CTX) and tartrate-resistant acid phosphatase type 5b (TRACP5b) were determined.
RESULTS: Men undergoing RRP were divided into those with lymph node-negative, localized (pT3, 101) and lymph node-positive (28) disease, after histological examination. The controls had the lowest marker levels while patients with bone metastases due to prostate cancer had the highest levels, with significance for ALP, osteocalcin and TRACP5b. Patients with lymph node-positive cancer had significantly high serum levels of TRACP5b and ALP but not for osteocalcin and S-CTX.
CONCLUSIONS: Bone turnover markers represent a new diagnostic tool in prostate cancer; the present data show that both bone resorption and bone formation are crucial for detecting bone metastases in prostate cancer. The value of bone turnover markers in high-risk patients should be evaluated in a longitudinal study.