Pathophysiology of bone metastases

Bone metastases are common complications of many cancer types (breast, prostate, lung). These skeletal lesions are usually osteolytic (excess of bone destruction), osteosclerotic (excess of bone formation) or mixed. Metastatic cancer cells residing in the bone marrow alter the activity of bone-resorbing (osteoclasts) and bone-forming (osteoblasts) cells and hijack signals coming from the bone matrix. In this review, we first show how cancer cells alter bone remodelling to promote the formation of osteolytic or osteosclerotic lesions. We next explain the reasons why cancer cells have bone tropism and survive in the bone marrow microenvironment.