A rare case of advanced metaplastic breast carcinoma with response to treatment with Sacituzumab govitecan

Metaplastic breast cancer is a rare variant of breast cancer with an extremely poor prognosis and limited treatment options. While standard chemotherapy has limited efficacy in treating metaplastic breast cancer, targeted therapies, immune modulating agents and antibody-drug conjugates may be promising alternatives. In this case report, we present a 72-year-old female diagnosed with metastatic triple negative metaplastic breast cancer who failed multiple lines of therapy including immunotherapy with atezolizumab and nab-paclitaxel but was able to achieve a sustained clinical response for nearly one year with the novel antibody drug conjugate Sacituzumab govitecan. Although Sacituzumab govitecan has been studied in metastatic triple negative breast cancer, its efficacy in treating metaplastic breast cancer has not yet been evaluated. To our knowledge, this report represents the first documented case of Sacituzumab govitecan being effectively used to treat metaplastic breast cancer.