Breast Cancer Metastasis to Bone: Look into the Future

Breast cancer is the most diagnosed cancer type and the leading cause of cancer-related death in women worldwide. Breast cancer has one of the highest survival rates worldwide, with a 5-year relative survival rate of 90% in the USA from 2012 to 2018 and an estimated 5-year relative survival rate of 15.4% worldwide for 2020. However, survival is affected by several parameters including the stage of the disease at the time of diagnosis and the presence of distant metastases. Therefore, the identification of the exact mechanisms involved in the formation of metastasis from breast cancer, as well as the development of innovative therapies, represents hot topics of scientific research in the field of oncology. The identification of a new cell type capable of forming distant metastasis into the bone, the breast osteoblast-like cells, provided new perspectives for both prevention and cure of patients affected by breast cancer. In this scenario, recent biological applications of nanotechnologies are opening innovative and intriguing perspectives for the treatment of metastatic lesions. Specifically, the use of engineering nanoparticles or exosomes could drastically improve the current armamentarium available from oncologists, thus improving life expectancy, as well as quality of life, of breast cancer patients.