Bone-Muscle Crosstalk in Advanced Cancer and Chemotherapy

Advanced cancers metastasize to distant sites and bone is a common site for metastases from breast, lung, and prostate cancers. Breast and lung cancer bone metastases typically lead to osteolytic lesions. Osteolytic bone metastases lead to bone pain, nerve compression, hypercalcemia, increased risk of fractures from falls, and muscle weakness. Bone metastases are incurable, and therapies for osteolytic lesions are aimed at reducing tumor burden and limiting bone loss. In addition to growth of tumor cells in bone, systemic effects to the musculoskeletal system are important in the overall reduction in mobility and increased morbidity. The focus of this chapter will be on the process of breast cancer cell colonization of bone, and bone-muscle crosstalk in breast cancer bone metastases and chemotherapy-induced bone loss. Much progress has been made recently in our understanding of the interplay between bone and muscle in cancer and chemotherapy, and future therapeutic strategies will likely include considerations for both of these tissues in the context of reducing overall tumor burden in bone.