High-dose chemotherapy with autologous stem cell rescue in breast cancer

Because metastatic breast cancer is a lethal disease despite some responsiveness to systemic chemotherapy, high-dose chemotherapy with autologous stem cell rescue is being utilized with increasing frequency. This analysis was undertaken to determine the outcome for such patients treated with intensive chemotherapy between 1989-1994, at the Hoag Cancer Center in Newport Beach, CA.

During 1989, only patients with metastatic disease who had failed more than two standard breast cancer chemotherapy regimens were considered eligible for such treatment. They received high-dose BCNU/cyclophosphamide/cisplatinum chemotherapy with autologous bone marrow rescue. After January 1990, patients with metastatic disease were eligible only if they had received limited prior chemotherapy and demonstrated responsiveness to induction chemotherapy. Beginning June 1990, patients with metastatic disease were to receive mitoxantrone and thiotepa (MiTepa) followed by peripheral blood stem cell rescue, then ifosfamide, carboplatin and etoposide (ICE) chemotherapy followed by peripheral blood stem cell rescue. High-risk adjuvant patients were to receive one course of ICE followed by rescue.

Between 1/89-12/94, 48 breast cancer patients underwent 65 intensive chemotherapy treatments followed by autologous stem cell rescue. During 1989, three of the eight patients with metastatic disease died within 60 days because of therapy-related complications. The longest failure-free survival (FFS) of these eight was 12.2 months, and the longest overall survival (OS) 20.5 months. Since 1/90, one physician has treated 24 patients with metastatic breast cancer, 17 of whom actually underwent two successive transplants with MiTepa/ICE. For the latter group, median FFS is 23.2 months; median OS is 39.7 months. There were no acute deaths, but two patients died > 60 days after initial transplant from therapy-related complications, veno-occlusive disease (5.2 months) and myelodysplastic syndrome (30.5 months), while five died of progressive disease at 22.5, 32.8, 39.4, 46.3, and 51.3 months. For the 24 metastatic patients treated 1990-1994, 1-, 2-, and 3-year FFS rates are 86%, 40%, and 17%, respectively, while OS rates are 91%, 80%, and 65%. Of 11 patients treated in the adjuvant setting, only one has relapsed (9.8 months) with follow-up from 3-61 months.

Modifications made in the program, including selection of patients responsive to induction chemotherapy, transfusion of peripheral blood stem cells, implementation of hematopoietic colony stimulating factors, and use of tandem intensive treatments has been associated with a low rate of acute morbidity and encouraging survival rates.