What is the evidence for rechallenging with anthracyclines or taxanes in metastatic breast cancer? A review of the data

Abstract

1072 Background: Anthracyclines and taxanes are widely used in the adjuvant setting for high risk, early stage breast cancer. This raises the issue of what is the optimal therapy for those patients who relapse, and what the potential role, if any, there is for rechallenge with these agents. The current evidence base for rechallenging with anthracyclines/anthracediones and taxanes in metastatic breast cancer (MBC) is examined in this study. Methods: Medline/Pubmed database searches were performed upto October 2008 to identify studies in which patients (pts) were rechallenged with anthracyclines/anthracediones or taxanes in MBC. Results: The efficacy data, as well as the safety data relating to neurotoxicity and cardiotoxicity from these studies, are summarized in the Table. Twenty-seven studies were identified (20=anthracycline/anthracedione, 7= taxane) of which only two were prospective studies. Both were small (n= 74 & 51) and related to anthracycline rechallenging. Conclusions: Evidence exists to support rechallenging with anthracyclines and taxanes. However, there are few prospective data on reexposure to taxanes and no data comparing anthracyclines versus taxanes following adjuvant exposure to both agents, supporting the need for clinical trials in this area. Such trials should ideally incorporate a cross-over design at treatment failure, which would shed light on the optimal sequence in which these agents should be administered. [Table: see text] No significant financial relationships to disclose.