Giada Maria Vecchio

1. Introduction Triple-negative breast cancer (TNBC) is defined by the lack of hormone receptors (HR) and epidermal growth factor receptor 2 (HER2) overexpression or amplification [1]. TNBC accounts for 15% of all breast cancers and is usually characterized by aggressive clinical behavior and a poor prognosis [2,3]. Recently, the introduction of next-generation sequencing (NGS) and omics technologies have defined several biological features of TNBC, showing considerable disease heterogeneity [4,5].

1. Introduction Brain metastases are the most common intracranial neoplasms in adults. The newly diagnosed brain metastasis incidence is 3 to 10 times higher than that of primary brain tumors [1].