Sustained complete remission of human epidermal growth factor receptor 2-positive metastatic breast cancer in the liver during long-term trastuzumab (Herceptin) maintenance therapy in a woman: a case report

INTRODUCTION: This case report and short review discusses how long trastuzumab should be continued in metastatic breast cancer, the safety issues in case of pregnancy and the risk of relapse with trastuzumab cessation. CASE PRESENTATION: We present the case of a 34-year-old Caucasian woman with human epidermal growth factor receptor 2-positive metastatic breast cancer in the liver who achieved prolonged complete remission within six months of receiving trastuzumab (Herceptin) in combination with vinorelbine and gemcitabine. The patient remains in complete remission seven years later and continues to receive trastuzumab as maintenance therapy. CONCLUSION: Trastuzumab-based therapies have greatly improved the survival rates of patients with human epidermal growth factor receptor 2- positive metastatic breast cancer. Despite such improvements, the safety of trastuzumab administration during pregnancy is yet to be defined.