Treatment of advanced and relapsing breast cancer with a combination of paclitaxel and mitoxantrone. South-Central Hellenic Oncology Group.

A multicenter nonrandomized study was designed to assess the efficacy (response rate and duration of relapse-free survival) and safety of the combination of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) 200 mg/m2 given as a 3-hour intravenous infusion with premedication every 3 weeks, followed by mitoxantrone 12 mg/m2, given as an intravenous push every 3 weeks, in patients with metastatic breast carcinoma. So far, 30 patients have entered the study and 27 are evaluable for response. All patients had advanced metastatic breast cancer and have been extensively pretreated with chemotherapy (28 patients), radiotherapy (13 patients), and hormonotherapy (24 patients). Fourteen patients (46.7%) have been previously treated with anthracyclines, and disease progressed in seven (23.3%) during anthracycline treatment. One patient had a complete remission and 14 a partial remission for a total remission rate of 55.6%. One of the 15 patients entering remission developed heart failure and was withdrawn from the protocol after 4 months in remission. She then relapsed and died 9 months after entering protocol. The remaining 14 patients continue to respond and their remission durations range from 4+ to 12+ months (mean, 9 months; 95% confidence interval [CI] 7.96 to 10.04). Eleven patients (40.7%) developed minor responses or disease stabilization lasting from 1.5 to 11.4+ (mean, 3.5 months; 95% CI, 1.9 to 6.0) and one of them had disease progression after 3.5 months and is still alive whereas another one who had disease progression died at 1.5 months. Four patients failed to respond and their disease progressed during protocol treatment; two of them died at 6.7 months while the other two are alive at 3.4 and 9.8 months. Overall survival ranged from 1.5 to 13+ months (mean, 6.7 months; 95% CI, 5.5 to 7.9). In the group of 14 anthracycline-pretreated patients, seven showed a partial remission, six a minor response or disease stabilization, and one had disease progression. Response duration ranged from 1.5 to 12+ months (mean, 6.1 months; 95% CI, 4.2 to 8.0); the three patients whose disease progressed died at 1.5, 6.7, and 8.8 months. Bone marrow toxicity was dose-limiting and caused treatment delays as well as dose de-escalation of both drugs in eight patients.