Osteoporosis during the hormonal therapy of prostate cancer and markers of bone tissue remodeling
Osteoporosis could be present in the different conditions: oncologic, endocrinologie and rheumatologic diseases, diseases of the gastrointestinal system, kidneys, lungs and also as the complication of the intake of somemedications (corticosteroids, gonadotropin-releasing-hormone analogues (GnRH-A), etc.). According to the literature data, osteoporosis develops in 40-50% of patients with prostate cancer after 2 years on GnRG-A. Osteodensitometry is a gold standard for diagnostics of the osteoporosis, but it allows not always to reveal the disturbances of the bone metabolism in oncologic diseases, especially at the earlier stage. In this review we show the contemporary evidence with biochemical markers of bone resorption (calcium, hydroxiprolin, NTX, CTX, PYD, DPD, TRAP-5b, bone sialoprotein - BSP) and markers of the bone synthesis (osteocalcin, AAF, AKF, KKF), their advantages and disadvantages. The level of these markers is increases in the most of the patients with osteoporosis and bone metastasis. The changes in the markers of the bone metabolism in the serum shown to be the relevant method of the efficacy estimation of the antiresorptive therapy in patients with secondary osteoporosis, including that, induced by the androgen deprivation therapy for prostate cancer. The main markers recommended are CTX and PINP. Hormonal therapy is a first line standard in patients with locally-advanced and metastatic prostate cancer. Bisphosphonates are the main medication for osteoporosis, induced by GnRG-A. We discuss the different regimens for the dosage and duration of the antiresorptive therapy using bisphosphonates.