Biweekly Docetaxel-Irinotecan Treatment with Filgrastim Support Is Highly Active in Antracycline-Paclitaxel-Refractory Breast Cancer Patients

Purpose: To evaluate the feasibility and activity of combination treatment with docetaxel (DTX) and irinotecan (CPT-11), given together every other week, combined with filgrastim support, in anthracycline- and paclitaxel-pretreated breast cancer (BC) patients. Patients and Methods: Advanced BC patients pretreated with anthracycline- and paclitaxel-based chemotherapy were eligible. DTX (80 mg/m 2 ) and CPT-11 (100 mg/m 2 ) were given biweekly with filgrastim support (300 µg/day on days 4–7). Results: Fifty patients (48 with metastatic and 2 with locally advanced cancer) were enrolled, with a total of 318 cycles being delivered. Thirty-one patients had visceral localizations. All patients had received epirubicin plus paclitaxel, with or without cisplatin, as front-line treatment for advanced disease. Overall, fatigue and diarrhea were the main chemotherapy-related toxicities in this study, being severe in 10 (20%) and 4 (8%) patients. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 18 (36%) and 6 (12%) patients, respectively. Red blood cell transfusions were required in 4 patients. A total of 32 objective responses were registered (overall response rate, ORR = 64%, 95% confidence interval = 49–77%), including 8 complete responses (16%). An additional 8 patients showed stable disease. After a median follow-up of 18 (range 4–29) months, 30 patients were still alive, and 19 were progression free; median progression-free and overall survivals were 10 and 23 months, respectively. Conclusions: Biweekly DTX/CPT-11 with G-CSF support is a well-tolerated and highly effective approach in anthracycline-/paclitaxel-pretreated patients. The very promising ORR and survival outcome observed in this subset of patients with a poor prognosis suggest that this regimen might play a major role in the management of this disease.