High-dose combination alkylating agent chemotherapy with autologous bone marrow support for metastatic breast cancer.

Seventeen patients with metastatic breast cancer were treated with a high-dose combination chemotherapy regimen and autologous bone marrow support. Thirteen patients had prior combination chemotherapy. Fifteen patients were treated with a phase II regimen of cyclophosphamide (5.625 g/m2), cisplatin (165 mg/m2), and BCNU (600 mg/m2). Bone marrow harvest and reconstitution were uncomplicated. All patients became profoundly myelosuppressed. Fourteen of 16 evaluable patients (88%) responded, including six complete responses (CRs) (38%). The median time to tumor progression was 5 months. The median survival was 8 months. CRs occurred more frequently in patients with no prior chemotherapy for metastatic disease, inflammatory breast cancer; and patients treated within 3 months of first recurrence. The rate of tumor regression was rapid, with a median of 11 days to partial response (PR) and 12 days to CR. Those patients achieving a PR by day 7 had a greater likelihood (P = .03) of attaining a CR than those patients whose PR occurred later. Three deaths (18%) occurred, all in women with inflammatory breast cancer treated with prior chemotherapy. High-dose combined alkylating agent therapy produced high PR and CR rates in metastatic breast cancer patients, most of whom had failed prior chemotherapy. The rate of tumor regression was rapid. Current efforts are directed at developing a regimen using drugs specifically active in breast cancer, with an intent of combining an effective high-dose regimen with additional modalities of therapy in the treatment of breast cancer.