High-dose chemotherapy of breast cancer.

High-dose chemotherapy (HDC) with stem cell autografting produces complete remission (CR) rates far in excess of those reported for lower-dose chemotherapy, or for any form of endocrine manipulation in patients with metastatic breast cancer. In early studies involving patients with resistant disease, HDC produced CR rates of as high as 25%. Most contemporary HDC trials accrue patients who are responding to "conventional" chemotherapy, and hence, few untreated patients have been studied in phase II evaluations. In one case, a CR rate of 54% (25% of which remained durable) was reported. In a randomized trial of high-dose versus conventionally dosed therapy, investigators in South Africa reported complete response rates of 50% and 6% respectively. In trials in which HDC is applied as a form of consolidation therapy following "conventional" chemotherapy, complete remission rates as high as 70% are reported.