title: The immune system and hormone-receptor positive breast cancer: Is it really a dead end?
abstract: Even if breast cancer has not been traditionally considered an immunogenic tumor, recent data suggest that immunity, and its interaction with tumor cells and tumor microenvironment, might play an important role in this malignancy, in particular in triple negative and HER2+ subtypes. As no consistent data on the potential clinical relevance of tumor infiltrating lymphocytes have been produced in hormone receptor positive (HR+) HER2- breast cancer, the interest in studying immune aspects in this subtype has become less appealing. Nevertheless, some scattered evidence indicates that immunity and inflammation may be implicated in the biology of this subtype as well. In HR+ breast cancer, the interaction between tumor cells and the immune milieu might rely on different mechanisms than in other BC subtypes, involving the modulation of the tumor microenvironment by mutual interplays of endocrine factors, pro-inflammatory status and immune cells. These subtle mechanisms may require more refined methods of evaluation, such as the assessment of tumor infiltrating lymphocytes subpopulations or gene signatures. In this paper we aim to perform a comprehensive review of pre-clinical and clinical data on the interplay between the immune system and breast cancer in the HR+ subtype, to guide further research in the field.
authors.affiliation: Dept. of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy; Division of Medical Oncology 2, Istituto Oncologico Veneto IRCCS, Padova, Italy. Electronic address: mariavittoria.dieci@unipd.it.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Dieci
authors.affiliation: Dept. of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy; Division of Medical Oncology 2, Istituto Oncologico Veneto IRCCS, Padova, Italy.
authors.forename: Gaia
authors.initials: G
authors.lastname: Griguolo
authors.affiliation: Division of Medical Oncology 2, Istituto Oncologico Veneto IRCCS, Padova, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Miglietta
authors.affiliation: Dept. of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy; Division of Medical Oncology 2, Istituto Oncologico Veneto IRCCS, Padova, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Guarneri
mesh_terms: D001943:Breast Neoplasms / Q000276:immunology* / Q000378:metabolism* / Q000628:therapy; D063646:Carcinogenesis / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000276:immunology / Q000378:metabolism / Q000628:therapy; D011960:Receptors, Estrogen / Q000378:metabolism*
chemical_list: D011960:Receptors, Estrogen
keywords: Breast cancer; Endocrine therapy; Estrogen receptor; Immune checkpoints; Immunity; Tumor infiltrating lymphocytes