Systemic Treatment of Bone Disease in Metastatic Urinary Malignancies

Context: Bone metastasis is a common site of metastatic disease in patients with genitourinary malignancies. Given that the presence of bone metastasis decreases survival and has a negative impact on quality of life impact, it is critical to optimize management of this patient population.

Objective: To systematically review literature on the systemic treatment of bone metastasis in prostate cancer, renal cell carcinoma, urothelial carcinoma, and germ cell tumors.

Evidence acquisition: We performed a nonsystematic critical review of PubMed/Medline, clinicaltrials.gov, and the Cochrane Library from January 2001 to February 2019. Identified reports were reviewed according to the Consolidated Standards of Reporting Trials, and selected based on reporting skeletal related events and symptomatic skeletal events for patients with urologic malignancies.

Evidence synthesis: Skeletal metastases occur frequently in genitourinary malignancies, at rates around 80% for patients with metastatic prostate cancer and 30% for patients with metastatic renal cell and urothelial carcinoma, and are uncommon in patients with germ cell tumors. Skeletal related events and symptomatic skeletal events can occur in these patients. Optimization of bone health involves dietary and lifestyle modifications, and use of osteoclast-targeted agents in select individuals. Additionally, disease-modifying agents, such as radiopharmaceutical, immunotherapy, and cMET inhibitors, which have activity in the bone, have improved outcomes for patients, including skeletal-related events and symptomatic skeletal events.

Conclusions: While the presence of bone metastases is associated with increased mortality and worse outcomes in patients with genitourinary malignancies, strategies have been developed to improve quality of life and survival for patients with skeletal metastases. Future studies investigating novel therapeutic options and bone supporting agents are warranted to target this patient population.

Patient summary: In this report, we reviewed the current literature and recent clinical trials involving treatment of bone metastases in urinary cancers. The use of bone-targeting agents can improve outcomes for patients, and additional lifestyle modification can optimize bone health in this population.