Short term high density systemic therapy for metastatic breast cancer

Abstract

Twenty-three patients with metastatic breast carcinoma were induced with a complex systemic therapy regimen in an attempt to ascertain if a complete remission rate greater than 50% could be obtained with intensive drug exposure. The durability of the remissions was observed by discontinuing therapy after 3 cycles in complete remission or after 6 cycles of treatment, whichever was longer. In 13 patients consolidation radiation therapy to the pre-treatment sites of disease was administered after discontinuing systemic therapy. Each 28 day cycle of the drug regimen consisted of pulses of adriamycin, vincristine, dibromodulcitol, prednisone, methotrexate with leukovorin rescue, hexamethylmelamine, bleomycin (discontinued after entry #17), fluoxymesterone, and tamoxifen. Eighteen of the 23 patients achieved complete remissions (78%) and 3 had partial remissions. The median times to treatment failure and survival were, respectively, 12.3 and 19.4 mos. The times for complete remission patients were, respectively, 13.5 and 23.9 mos. Consolidation radiotherapy at greater than or equal to 40 Gy to drug induced pre-study sites of complete remission was associated with first relapses at pre-study sites in 5/30 (17%) instances, compared to 21/35 (60%) in sites not receiving radiotherapy. Side-effects were commensurate with the intensity of the treatment program and are detailed in the text. Although the achievement of a high complete remission rate is promising, the failure to extend their duration beyond that of historical data suggests that additional conceptual and therapeutic approaches need to be explored.