Response to Lapatinib-Capecitabine combination in a young patient with recurrent HER2-positive breast cancer refractory to two lines of therapy with anti-HER2 drugs

HER2-positive breast cancer is an aggressive tumour that affects approximately one in five breast cancer women. Clinical studies have shown that HER2-positive cancer have different characteristics from other mammary tumors: a more rapid progression of the disease, an earlier age of onset (women of childbearing age between 30 and 45 are also affected to a large extent), a different response to chemotherapyand, in general, an unfavorable prognosis. Breast cancer with overexpression of the HER2 protein may benefit from the latest generation of target treatments (monoclonal antibodies and anti-HER2 tyrosine kinase inhibitors). Not all HER2-positive tumors, however, respond to therapies, and some responders may later become resistant. We report the case of a young woman with HER2-positive mammary carcinoma who presented resistance to the first two treatment lines with anti-HER2 drugs (trastuzumab-pertuzumab and TDM1) and responded to the combination lapatinib-capecitabine in third line (Oncology).