Weekly paclitaxel: an effective and well-tolerated treatment in patients with advanced breast cancer.

The rationale for dose-dense weekly paclitaxel in the treatment of breast cancer is that more frequent delivery of more moderate doses may achieve greater efficacy than larger doses given less often through more sustained exposure of dividing tumor cells to cytotoxic drugs. Weekly paclitaxel has been used successfully in the treatment of advanced breast cancer, as single-agent therapy, in combination chemotherapy, with radiotherapy and with immunomodulating drugs, such as trastuzumab. Many of the patients in these studies have received previous chemotherapy regimens. Nevertheless, response rates with weekly paclitaxel up to 86% have been achieved with single-agent therapy, up to 87% with combination therapy and up to 100% when combined with radiotherapy. Paclitaxel given weekly together with the humanized monoclonal antibody against HER2, trastuzumab, has shown response rates of 50-82% in patients with aggressive HER2-positive tumors. Paclitaxel is associated with moderate toxicity. Its main dose-limiting toxicities are neutropenia and peripheral neuropathy, but these are generally manageable.