New horizons in breast cancer: the promise of immunotherapy.

Immunology and immunotherapy of cancer is an expanding field in oncology, with recent great achievements obtained through the new successful approaches implemented to circumvent immune evasion, which is undoubtedly considered a novel hallmark of cancer. Translational research in this topic has revealed targets that can be modulated in the clinical setting with new compounds and strategies. Like most of the tumors, breast cancer is considered a complex and heterogeneous disease in which host immune responses have been also recently demonstrated of critical relevance. T infiltrating lymphocyte measurement is suggested as a powerful new tool necessary to predict early breast cancer evolution, especially for the her2-positive and triple-negative subtypes. Other biomarkers in tissue and peripheral blood are under intense scrutiny to ascertain their eventual role as prognostic and/or predictive factors. This background has fueled the interest in developing clinical research strategies to test activity of modern immunotherapy in breast cancer, which constitutes the main focus of this review.