Cyclophosphamide/mitoxantrone/melphalan (CMA) regimen prior to autologous bone marrow transplantation (ABMT) in metastatic breast cancer.

Dose-intensive treatment followed by ABMT is currently used in different approaches to treat breast cancer patients. An active non cross-resistant regimen combining cyclophosphamide (C), mitoxantrone (M) and melphalan (A) (CMA), was developed as the conditioning regimen before ABMT. The purpose of this phase II study was to evaluate this protocol and the duration of its effect in metastatic patients, who responded to chemotherapy. Criteria for inclusion included histologically documented breast cancer, age < 55 years and the first detection of measurable metastatic lesions. Following first-line chemotherapy in responding patients, histologically negative bone marrow was collected and cryopreserved. Then, intensification with cyclophosphamide (120 mg/kg), mitoxantrone (60 mg/m2), and melphalan (140 mg/m2) was followed by ABMT. Sixty-one metastatic breast cancer patients with a mean age of 40 years were included. Sites of measurable metastases included: liver 24, lung 14, central nervous system four, pleura three, skin six, and chest wall six, nodes eight and bone marrow one. Nineteen patients had lesions in two or more sites, and 22 had bone involvement. The response of 60 patients could be evaluated: before ABMT 31 were in clinical complete response (CR), 22 in partial response > 50% (PR), and seven had new progression. After ABMT, 36 patients were in CR, 16 in PR, one progressed and one was stable. Seven (11.5%) toxic deaths occurred. Mean time for hematological recovery was 32.5 days, without hematopoietic growth factors. Median survival was 33 +/- 9.4 months from the start of therapy, and 25.7 +/- 4.6 months from the date of ABMT. Median event-free survival was 20 months from the start of therapy, and 13 +/- 2 months from ABMT. With a median follow-up of 51 months, probability of actuarial survival, measured from the beginning of initial chemotherapy, was 36%, and event-free survival was 18%. In metastatic breast cancer responding to chemotherapy, high-dose consolidation with CMA and ABMT resulted in a median survival of 33 months. These results lay the ground work for evaluation in a randomized trial in metastatic breast cancer.