Breast Cancer: High-Dose Therapy.

Area of Science:

• Oncology
• Hematology
• Clinical Trials

Background:

• Breast cancer is a leading indication for high-dose chemotherapy with autologous stem cell rescue (HDC/ASCR).
• The use of HDC/ASCR has increased based on promising results from phase II studies.
• Concerns exist regarding selection bias in non-randomized studies influencing outcomes.

Purpose of the Study:

• To review early and phase II studies of HDC/ASCR for breast cancer, focusing on long-term follow-up.
• To discuss the impact of selection bias on the outcomes of HDC/ASCR studies.
• To evaluate randomized studies of HDC/ASCR and its current recommendation in clinical trials.

Main Methods:

• Review of early dose-intensification studies and phase II HDC/ASCR trials for metastatic and high-risk breast cancer.
• Analysis of studies with long-term follow-up to assess outcomes.
• Examination of randomized controlled trials comparing HDC/ASCR to standard chemotherapy.

Main Results:

• Phase II studies suggested higher response rates and survival times for HDC/ASCR compared to historical controls.
• Evidence indicates significant selection bias in non-randomized phase II studies of HDC/ASCR.
• Few randomized comparisons of HDC/ASCR versus standard chemotherapy are available.

Conclusions:

• Currently, HDC/ASCR for breast cancer should only be administered within a clinical trial setting.
• Further results from large randomized trials are needed to establish the definitive role of HDC/ASCR in breast cancer treatment.
• The potential benefits of HDC/ASCR require validation through rigorous randomized studies to overcome selection bias concerns.