BONE MICROENVIRONMENT AND ITS ROLE IN BONE METASTASIS

Bone is a common site for cancer metastasis. The development of bone metastases represents a serious progression in a patient with cancer, leading to treatment goals changing from curative to palliative. Cancers that have metastasised to the bone are resistant to therapies and lead to destructive and painful changes in bone structure. Here we describe the multiple steps in metastasis and the varying processes that drive tissue selectiveness. There is an emphasis on the basis of the fertile 'soil' for cancer growth that is provided by the bone microenvironment. The basic changes in host/cancer cell interactions as a metastatic cancer cell invades the bone, escapes dormancy to grow to a micro metastasis, induces angiogenesis and hijacks the normal physiological processes of bone remodelling to fuel its own growth are outlined. Steps in the process of metastasis that offer potential as therapeutic targets are briefly discussed.