High-dose chemotherapy in breast cancer: where are we now?

High-dose chemotherapy (HDCT) with peripheral blood stem cell support is often used in high-risk patients with breast cancer. Most investigators performing these procedures provide anecdotal experience that complete remissions occur more commonly with HDCT than standard therapy. However, prospective studies have not convincingly demonstrated an advantage of HDCT in either the adjuvant or metastatic disease setting. The emergence of newer agents, such as the taxanes and trastuzumab, and their incorporation into treatment regimens may create a new standard against which HDCT must be evaluated. In addition, the heterogeneity of breast cancer patients represents an important barrier that must be addressed in future evaluations of HDCT. New prospective, randomized, clinical trials of HDCT are needed, which will incorporate the newer anticancer agents in standard therapy and enroll patients according to multiple well-defined risk factors. Until these studies are conducted, many questions will remain unanswered concerning the role of HDCT in breast cancer. Given its encouraging results in other malignancies, there is ample evidence to continue evaluating HDCT in controlled clinical trials.