An overview of phase II studies of docetaxel in patients with metastatic breast cancer.

Docetaxel is a new taxoid drug with good activity against human breast cancer cells in vitro; a number of partial and minor responses have been obtained during phase I studies in patients with advanced breast cancer. In phase II trials, first-line use of docetaxel has produced an overall response rate (OR) of up to 73%. In addition, docetaxel has shown good activity when given as second-line therapy (OR 38%), particularly in patients with disease refractory to anthracyclines (OR 55%). Indeed, the high response rate in this latter group of patients clearly warrants further investigation of docetaxel in this setting. Neutropenia is the major dose-limiting toxicity of docetaxel, but other haematological effects are rare. Hypersensitivity and cutaneous reactions are ameliorated by premedication with corticosteroids and histamine antagonists; fluid retention may improve with longer use of prophylactic premedication. Docetaxel is mildly emetogenic, but no other premedication is necessary. In summary, docetaxel is an active new drug in the treatment of advanced breast cancer. Its role in the management of early stage disease awaits the results of prospective randomised trials.