As prostate cancer progresses, bone is one of the most common sites of metastases. More than 80% of men with metastatic prostate cancer have radiographic evidence of bone involvement.¹ The bone lesions associated with prostate cancer result in increased but unstable bone formation which leads to fragile bone that can easily fracture or collapse. The clinical manifestations include considerable pain, fracture, spinal cord compression, and ineffective hematopoiesis.¹

Current methods of treatment for prostate cancer are prostatectomy, radiation therapy and hormone therapy. Androgen deprivation therapy (ADT) by either bilateral orchiectomy or administration of a long-acting gonadotropin-releasing hormone (GnRH) agonist is the standard treatment for advanced prostate cancer. Bilateral orchiectomy or GnRH agonist therapy have equivalent response rates and response duration.² Treatment is palliative, improves quality of life, and may delay time to disease recurrence for men at high risk of recurrence.³

In men with prostate cancer, ADT can decrease bone mineral density and increase fracture risk, apart from the direct of metastatic cancer. This is referred to as treatment-related osteoporosis in men with prostate cancer. It is also referred to as cancer-treatment–induced bone loss, or CTIBL. Preventing the adverse skeletal effects of long-term ADT is important, especially since this treatment often is used in men with relatively long life expectancies.⁴