Adjuvant Radiotherapy on Circulating Cells in Breast Cancer Patients

Every year, around one million women are newly diagnosed with breast cancer. Early screening and adjuvant treatments with curative intent such as radiotherapy, hormone therapy, chemotherapy, immunotherapy, have reduced the incidence of breast cancer specific mortality. Despite this, breast cancer remains the main cause of cancer mortality in Europe. The primary cause is due to metastases development in different organs, such as lung, liver, bones and brain. A significant decrease in mortality in breast cancer patients is likely to be achieved by preventing the formation of metastases or by implementing the efficacy of their treatment. Radiotherapy is one of the pillars of breast cancer adjuvant treatments with important survival benefits. Mutual and dynamic communications between tumor cells and the tumor microenvironment (TME) influence the development and evolution of the tumor as well as the appearance of distant metastases. The mediators of the immune and inflammatory response that constitute TME, as well as mediators of tumor progression, are also considered "targets" of future therapeutic strategies. Radiation applied to the preserved breast during radiotherapy treatment activates numerous molecular cascades in tumor bed adjacent cells causing an inflammatory state. During this process, pre-clinical studies demonstrated CD11b + and CD11b+cKit+cells mobilization in the blood. These cells are involved in numerous processes during tumor progression/control and metastases development. The results allow us to investigate the development of innovative therapeutic and monitoring strategies. The clinical repercussions would consist in identifying new predictive and prognostic targets in breast cancer.