Bone-marker levels in patients with prostate cancer: potential correlations with outcomes

Abstract

The skeleton is typically the first site of metastasis in patients with prostate cancer, and bone metastases can result in severe bone pain and potentially debilitating fractures. Although bone scans are a reliable means of assessing osteoblastic lesions, tools for monitoring early changes in bone health are lacking. Biochemical markers of bone turnover might fulfill this unmet need. Correlative studies have suggested that bone-marker levels may have utility in assessing disease progression and response to bone-directed therapy. Elevated levels of the markers, N-telopeptide of type I collagen and bone-specific alkaline phosphatase, are associated with higher rates of death and skeletal-related events in the bone metastasis setting. Marker levels also correlate with response to zoledronic acid treatment, and similar data with the investigational agent, denosumab, are emerging. Changes in bone-marker levels reflect alterations in skeletal homeostasis and can provide important insights into bone disease progression and response to bone-directed therapy in patients with prostate cancer. More mature data from currently ongoing clinical trials will provide further insight on the utility of marker assessments as an adjunct to established monitoring methods in prostate cancer.