Current concepts and trends in the treatment of bone metastases in patients with advanced prostate cancer

Bone metastases have a major impact on quality of life and survival of patients with advanced prostate cancer. In the last decade, the development and approval of substances inhibiting the vicious cycle of bone metastases have enabled the reduction of complications caused by bone metastases in patients with castration-resistant prostate cancer. These drugs have raised awareness of the importance of skeletal-related events which in the meantime represent an important end point also in trials using agents not specifically designed for bone lesions. Second-generation antihormonal drugs such as enzalutamide or abiraterone have been shown to have a positive impact on the incidence of skeletal complications and therefore provide an important tool in the armamentarium used for treating bone metastases. Radiopharmaceuticals such as radium-223 dichloride ([(223)Ra]) have been demonstrated not only to reduce skeletal-related events and bone-related pain, but also to prolong overall survival, thereby being the first bone-targeting agent showing a survival benefit. As previous studies have not provided an obvious benefit of bone-targeted lesions in castration-sensitive disease, the use of these agents is not recommended. In oligometastatic prostate cancer, the role of local treatment of metastases using stereotactic radiation or radiosurgery is a matter of intense debates and may play an increasing role in the future.