High-dose chemotherapy with autologous stem cell rescue for breast cancer: yesterday, today and tomorrow.

Metastatic breast cancer remains incurable by conventional means and is the second leading cause of all cancer deaths in women in the United States. Laboratory and clinical studies have shown chemotherapy dose intensity may be important in breast cancer therapy, and therefore clinical trials have been investigating high-dose chemotherapy (HDC) with autologous stem cell rescue (ASCR) for the past decade. Initial Phase I trials in heavily pretreated patients demonstrated good response rates but short survival times. The next generation of trials used HDC as initial treatment for metastatic breast cancer and showed improved results. Most recently, patients receive HDC after "induction" chemotherapy to minimize tumor burden prior to HDC. Results from these most recent trials are encouraging, with complete remissions (CR) achievable in at least half of patients and long-term survivors noted. An ongoing randomized trial of HDC versus conventional chemotherapy should answer whether HDC is superior to conventional chemotherapy for metastatic breast cancer. Based on encouraging data from a preliminary trial, two ongoing randomized trials are comparing HDC versus conventional chemotherapy in high-risk primary breast cancer. Technological improvements, better supportive care and experience have all contributed to decrease the morbidity and mortality of this procedure. Additionally, hospitalizations have become shorter and costs may be decreasing. This review will discuss the issues pertinent to this modality in the past and present, including chemotherapy regimens, stem cell technology and related issues, outcomes, ongoing trials and future directions for consideration.