HER2-positive metastatic breast cancer: a changing scenario

Adjuvant trastuzumab (AT) dramatically improved HER2-positive breast cancer prognosis. Relapsed disease after AT has different patterns and information is available from observational studies. In this Review Chemotherapy regimens combined to anti-HER2 blockade are discussed, focusing in particular the role of anthracyclines, taxanes and capecitabine. The use of trastuzumab beyond progression and the role of other anti-HER2 agents like lapatinib, pertuzumab and T-DM1 are explored, as also dual blockade and in trastuzumab resistant Patients. Metastatic "de novo" HER2 Luminal (co-expression of HER2 and hormone receptors) Patients are eligible for anastrozole and trastuzumab but if pretreated with trastuzumab they are also eligible for lapatinib and letrozole. In any case endocrine treatment plays a complementary role to chemotherapy which remains pivotal. The last topic explored is treatment options for patients with brain metastases where both trastuzumab given concurrent with radiotherapy or lapatinib and capecitabine appear as potentially active.