Docetaxel in combination with mitoxantrone and granulocyte colony-stimulating factor as front-line chemotherapy in metastatic breast cancer: A multicenter phase II study

Purpose: To evaluate the activity and tolerance of docetaxel in combination with mitoxantrone and granulocyte colony-stimulating factor (G-CSF) as front-line treatment in patients with metastatic breast cancer (MBC). Patients and methods: Fifty-four previously untreated patients with MBC who had bidimensionally measurable disease were enrolled onto the study. Forty-eight (89%) patients had visceral metastases and nineteen (36%) had relapsed within twelve months following adjuvant chemotherapy. Docetaxel (100 mg/m(2)) was given on day 1 after appropriate premedication and mitoxantrone (20 mg/m(2)) on day 8. G-CSF (150 mcg/m(2)/d s.c.) was administered from day 2 to day 6 and from day 9 to day 15. The regimen was repeated every three weeks, on an outpatient basis. Results: In an intention-to-treat analysis, 9 (17%) CRs, 24 (44%) PRs, (overall response rate 61%; 95% confidence interval (CI): 48.1%-74.1%), 12 (22%) SD and 9 (17%) PD were observed. The median duration of response and the median time to tumor progression was 12.5 and 14 months, respectively. The overall median survival was 16.5 months, whilst the probability for one- and three-year survival was 61% and 35%, respectively. Grade 3-4 neutropenia occurred in 37 (69%) patients, and febrile neutropenia in 16 (30%); there was one death due to sepsis. Grade 3-4 thrombocytopenia occurred in four (8%) patients. Grade 2-3 neurosensory toxicity was observed in 8 (15%) patients and grade 2-3 asthenia in 24 (45%). Conclusions: Docetaxel in combination with mitoxantrone and G-CSF support is an intensified and active front-line regimen for patients with MBC; despite its hematological toxicity, this regimen merits further comparison with other standard anthracycline- and/or taxane-based combinations.