Serum osteocalcin concentration in patients with prostatic cancer.

Fifty-four subjects were studied: 36 advanced prostatic adenocarcinoma patients in stage D and 18 normal age-matched male controls. Serum alkaline phosphatase, serum acid phosphatase, plasma osteocalcin, 24-h urinary hydroxyproline excretion, and 24-h whole-body retention of [99mTc]-methylene diphosphonate were measured in all subjects before and 3, 6, and 9 weeks after the start of treatment. Skeletal metastases were identified by radiography and/or [99mTc]-methylene diphosphonate bone scan. The results confirm that acid phosphatase is a significant marker in prostatic cancer; serum alkaline phosphatase may be useful in the evaluation and monitoring of bone metastases but it is not always specific; urinary excretion of hydroxyproline is an index of osteoclastic activity; serum osteocalcin may be considered more specific in the evaluation and monitoring of osteoblastic bone metastases in prostatic cancer.