Immunotherapy Strategies in the Treatment of Breast Cancer

Background: Advances have been made in the field of cancer immunotherapy in understanding the role of the host immune response in affecting tumor progression and response to various treatments. Through these advances, two novel immunotherapies were introduced in the clinic for melanoma and prostate cancer. Methods: This review discusses the available data regarding the immune-modulating effects of various treatments and how they can be utilized in the treatment of breast cancer. Databases including PubMed and Google Scholar were searched using terms including breast cancer, vaccines, and immunotherapy. Results: There is increasing evidence to support that certain breast tumors are intrinsically more immunogenic than others. Tumors that elicit more potent cytotoxic T-cell responses tend to have a more favorable prognosis and respond better to chemotherapy than less immunogenic tumors. Many standard treatments used in breast cancer rely in part on their immunogenic effects for their success in eradicating disease. Understanding how to use these agents to effectively augment the antitumor immune response may lead to better outcomes. Finally, many new immunomodulatory agents and vaccines that can reverse the immunosuppression caused by established tumors are in development. Combining these novel agents with current therapies may boost their efficacy. Conclusions: Immunotherapeutic approaches combined with novel sequences of chemotherapies, radiation, vaccines, and immunomodulating agents hold promise for enhancing the treatment of breast cancer.