Complete response of severe symptomatic bone marrow metastases from heavily pretreated breast cancer with a 3-weekly trastuzumab schedule. A clinical case.

Overexpression of HER-2/neu in breast cancer has been associated with more aggressive disease and poor overall survival. Trastuzumab, a recombinant humanized monoclonal antibody with high affinity for the HER-2 protein, inhibits the growth of breast cancer cells overexpressing HER-2. Trastuzumab showed, as second-line treatment, 15% of objective response in metastatic breast cancer. Bone marrow metastases are detectable in 23% of the patients with advanced breast cancer at first relapse and this rate increases in patients with metastatic disease. We report a case of a complete response of bone marrow metastases from breast cancer using a 3-weekly trastuzumab schedule, in a heavily pretreated patient with severe symptomatic pancytopenia.