2. Department of Medicine, Michigan State University, USA.
Breast cancer is one of the most commonly diagnosed cancers in women and is also the leading cause of death. Metastatic and recurrent breast cancer is associated with poor prognosis. Despite advanced multidisciplinary approaches in breast cancer treatment, there are still many therapeutic failures resulting in recurrence, metastasis, and death. Researchers have postulated that an appropriate microenvironment is needed for the growth of the tumor cells. As a result, there has been increased interest in developing innovative therapies targeting the microenvironment. Although chemotherapy is capable of inducing cytotoxic T cell infiltration within the tumor microenvironment, the efficacy of the antitumor immune responses may be limited by the development of immunosuppressive networks. Improved understanding of immune tumor promoting and antitumor mediators in breast cancer has created new opportunities for targeted therapies. Immunotherapy with immune checkpoint inhibitors is beginning to show promise for breast cancer. Adoptive T cell therapy remains an active research area in patients with breast cancer. This review summarizes the current knowledge of immune breast cancer microenvironment and outlines the innovative therapeutic regimens, including T cell based immunotherapy and combination regimens with immune checkpoint inhibitors, which are under clinical investigation.
Keywords: Tumor infiltrating lymphocytes, immunotherapy, breast cancer, biomarker