Biochemical bone markers in breast cancer.

Bone metastases, the most common metastatic manifestation of many cancers, including breast cancer and prostate cancer, contribute significantly to the pain and disability often associated with later stages of malignant disease. Although bisphosphonates have demonstrated efficacy in the treatment of metastatic bone disease (MBD), identifying patients most likely to develop bone metastases (and thus to benefit from treatment) is a challenge. In recent years, advances in understanding the pathophysiologic underpinnings of bone metastases have led to the discovery of several potential markers for dysregulation of bone coupling. Trials have been conducted to validate these biochemical markers and to explore their possible role in measuring efficacy of bisphosphonate treatment and of other metastatic bone therapies. In no area is this research more important than in the management of breast cancer. Although the value of these bone turnover markers is still unclear, and further research is necessary, results from these recent trials indicate some correlation.