Efficacy of sunitinib in patients with renal cell carcinoma with bone metastases

Bone is the second most common metastatic site in patients with renal cell carcinoma presenting with metastases (mRCC) at diagnosis. Complications of metastatic bone disease, including bone pain, fractures, spinal cord compression, and hypercalcaemia, are the primary cause of decline in the quality of life of patients with mRCC. Currently, treatment for mRCC bone metastases is generally palliative. Bisphosphonates are also used; however, the efficacy of bisphosphonates in conjunction with targeted agents is currently unknown. As growth factors play a critical role in the development of bone metastases, there is a biological rationale for the use of targeted agents to treat them. We report here the case of two patients with mRCC with surgically unresectable sacral bone metastases treated with sunitinib, who are still alive with long-term stabilization of metastases of 48 and 31 months. Results suggest targeted agents such as sunitinib may be an effective treatment for bone metastases.