Mechanisms of breast cancer dormancy in bone metastasis

Bone metastasis remains a serious threat to breast cancer patients. This condition arises from the outgrowth of previously dormant tumour cells in this site. Dormant tumour cells are almost impossible to detect in human patents, and these cells acquire "stem like" characteristics rendering them resistant to current cancer therapies. Furthermore, the development of therapies to target this population has proved challenging. The bone marrow is a particularly permissive environment for tumour cell dissemination and dormancy, but the mechanisms regulating this process remain to be completely elucidated. Expansion of our understanding of the mechanisms underlying tumour dormancy is critical to the development of targeted therapies and thus, the prevention, or treatment, of metastatic disease. This review aims to explore mechanisms of tumour dormancy in bone, in detail, focusing specifically on breast cancer dormancy. In addition to subsequent discussion of traditional and new, state of the art, methods of studying dormancy to aid further research efforts.