Serum osteocalcin in monitoring bone metastases in advanced prostatic cancer

Osteocalcin, a K-dependent vitamin protein, was studied in a group of advanced prostatic carcinoma patients to test the usefulness of this marker for diagnosing bone metastases. Osteocalcin levels were above the norm in 22 out of 27 patients with bone metastases, although high levels were not observed in patients without bone metastases. High sensitivity and specificity levels of serum osteocalcin appear to be strongly correlated to metastatic bone involvement and disease relapse after hormone treatment. Although these results must be confirmed on a larger series of patients, this protein appears to be a useful biological marker in prostatic cancer.