Carboplatin in combination as first-line therapy in advanced breast cancer

Carboplatin, a platinum analog with single-agent activity in previously untreated breast cancer, is characterized by comparatively less renal toxicity and emesis than cisplatin. We combined carboplatin at different dose levels [from 200 to 350 mg/m² by intravenous (IV) infusion on day 1] with 5-fluorouracil (500 mg/m² IV on days 1 and 8) and cyclophosphamide (500 mg/m² IV on day 1), with all three drugs recycled every 28 days, to evaluate anti-tumor activity and toxicity of this novel combination [5-fluorouracil/carboplatin/cyclophosphamide (FCC)] in untreated locally advanced (LABC) or metastatic breast cancer (M+). Of 37 patients treated between March 1990 and August 1991 [LABC 25, M+ 8; World Health Organization (WHO) performance status, 0-1; median number of treatment cycles, 5; median follow-up, 20 months], 33 are evaluable for response and toxicity. The overall complete plus partial remission rate was 57% (LABC 68%, M+ 25%). The median duration of response was 19+ months. The cumulative carboplatin dose ranged from 800 to 2350 mg/m² (median, 1450 mg/m²). In this series, no correlation was observed between the carboplatin dose level and response rate or toxicity. Leukopenia and thrombocytopenia represented the most frequent toxicities. WHO grades 3 and 4 neutropenia were documented in 34% and 8% of patients, respectively. Thrombocytopenia below 50 ×10⁹/l was observed in 8%. No renal toxicity was observed, and moderate emesis occurred in 67% of patients. These results indicate that FCC is an active and relatively safe combination for the treatment of advanced breast cancer in patients not previously treated with chemotherapy.