The verdict is not in yet. Analysis of the randomized trials of high-dose chemotherapy for breast cancer

Abstract

BACKGROUND: The relative efficacy of high-dose chemotherapy (HDC) compared to standard treatment for high-risk primary (HRPBC) or metastatic breast cancer (MBC) constitutes an area of intense controversy among the medical oncology community. A number of randomized trials have been conducted to address this issue. In most cases, the results of these trials are premature and contradictory. Furthermore, they have often been interpreted, incorrectly in this author's judgment, as proof of lack of benefit of HDC. EVIDENCE AND INFORMATION SOURCES: The results of studies published in peer-reviewed medical journals or presented in scientific meetings are discussed. In some cases, the status of the studies was determined through direct communication with the trial's principal investigator. RESULTS: The encouraging results of phase II trials suggested a benefit for HDC in important categories of patients with breast cancer. It has been argued that selection of patients might have been a critical factor in those studies. The results, in most cases preliminary, of numerous randomized trials in metastatic and high-risk primary disease cannot offer a definitive answer to this crucial question as of yet. Important concepts in the interpretation of these studies, such as size and statistical power, length of follow-up, magnitude of clinical benefit, and broad applicability of the results, are discussed in this review. CONCLUSIONS: The role of HDC for HRPBC or MBC patients remains undefined. Longer follow-up and mature analyses of the randomized trials are necessary before definitive conclusions are drawn. In the meantime, it is imperative that research continues, to enhance the efficacy of the procedure through innovative strategies.