Bone Metastases

Skeletal metastases occur when cancer cells from a primary tumor invade the bone and affect osseous tissue responsible for formation, mineralization, and resorption of the bone. Most bone metastases arise from prostate, breast, and lung primary tumors spreading to the bone, and disrupting the balance between osteoblasts and osteoclasts. Depending on the phenotype of the target cells, osteoblastic, osteolytic or mixed bone metastases will occur. The occurrence of bone metastases is associated with poor prognosis. In addition to low life expectancy, quality of life is diminished as patients with skeletal metastases experience pathologic fractures, pain, hypercalcemia, and bone marrow aplasia. A better understanding of the molecular pathways involved in the interaction between a cancer cell and the bone microenvironment is needed to address the prevention of skeletal metastases and to identify better treatments for patients who suffer from this type of malignancy. The bone microenvironment is highly complex and important processes such as hematopoiesis, osteogenesis and osteolysis are carried out in this microenvironment. Previous studies have demonstrated that many molecular mechanisms are involved in promoting cancer cell residency in the bone through the chemotaxis in bone niches. Moreover, even if many cancer cell types can enter the bone remaining in a dormant state, several transformed cells will exit from this dormancy. It remains unclear which factors trigger, and which limit this process. Immune surveillance plays a central role in limiting bone metastases colonization. However, several components of the immune system, such as infiltrating plasmacytoid dendritic cells, have been identified as promoters to facilitate bone metastases. A multidisciplinary approach is necessary to better define the biology, as well as the clinical approach, and treatment of bone metastases in order to improve the quality and the life expectancy of bone metastatic patients.

This Research Topic aims to discuss the above-mentioned aspects of bone metastasis including, but not limited to the following:

1) Epithelial-Mesenchymal Transition (EMT)
2) Cell migration, osteoclast activation
3) Cancer-induced osteolysis
4) Immune surveillance
5) Bone fractures, and bone metastases management
6) Incidence and risk factors

Authors are welcome to submit an Original Research or a Review article to provide readers with up-to-date knowledge in the field of bone metastasis.