Dose intensive therapy with autologous blood stem cell transplantation in breast cancer

Breast cancer is the commonest form of cancer in Australian women. Although approximately 50% of women with breast cancer achieve long term survival by current management methods, recurrent or metastatic disease is generally incurable. In addition, women with Stage II disease with > 10 positive axillary lymph nodes and also women with locally advanced disease (Stage III) have a poor survival even with adjuvant therapy.

To assess the toxicity and efficacy of high-dose chemotherapy with autologous peripheral blood stem cell (PBSC) transplantation in women with both metastatic and poor prognosis primary breast cancer.

Twenty-eight women with either metastatic (15) or poor prognosis (13) primary breast cancer were enrolled in the study between November 1988 to January 1993. PBSC were harvested using high-dose cyclophosphamide (Cy) with or without granulocyte-colony stimulating factor (G-CSF) and a myeloablative regimen of Cy, melphalan and carboplatin (CMCp) was used in the transplantation phase.

Optimum numbers of stem cells were harvested in 85% of patients. The use of five G/m2 Cy plus G-CSF resulted in better PBSC yields and a significant reduction in haematologic morbidity when compared to mobilisation with Cy alone. Twenty-two women underwent 23 PBSC transplants (PBSCT). There have been two early deaths due to sepsis. The predominant morbidities observed following high dose chemotherapy and transplantation have been nausea, mucositis and diarrhoea. The median number of days to discharge following infusion of PBSC was 15 (range 11-21). At a median follow up time of 1.1 years (range 0 months-3.6 years), 8/22 (36%) evaluable patients remain alive and disease free while 14/22 (64%) have relapsed or progressed or died.

High-dose chemotherapy and autologous PBSCT is a potentially highly effective treatment of women with metastatic and poor prognosis primary breast cancer. Randomised studies are required to compare this form of therapy to more standard forms of treatment in breast cancer.