[Pharmacological study of weekly docetaxel in patients with metastatic breast cancer]

A pharmacological comparison of weekly administrations of docetaxel (TXT) and standard/conventional TXT was carried out among patients with metastatic breast cancer. Fifteen patients were enrolled in this study of weekly TXT (TXT: 40 mg/body/week x 3 with 1 week interruptions in 10 patients) and standard TXT (TXT: 60 mg/m2/3 weeks in 5 patients). The median dose intensity (DI) of weekly TXT (20.63 mg/m2/week) was similar to that of standard TXT, and the median relative dose intensity (RDI) of weekly TXT was 0.98. The median area under the plasma concentration-time curve (AUC) of weekly TXT (1.20 micrograms.h/ml) was smaller than that of standard TXT (1.87 micrograms.h/ml). Therefore, there were remarkable decreases in both median percent of decrease in neutrophil counts and grade 3, 4 neutropenia with weekly TXT. These pharmacological data show that weekly TXT is a well-tolerated and feasible schedule for the treatment of metastatic breast cancer.