The Role of Anthracyclines/Anthraquinones in Metastatic Breast Cancer

Abstract

Anthracyclines are considered to be one of the most active agents in metastatic breast cancer (MBC). At the eqiumolar doses of epirubicin and doxorubicin in MBC there is no difference in either response rates or time to progression but there is a statistically significant reduction in cardiac toxicity and myelosupression. The results received in studies evaluating the role of dose intensity, showed that the increase of dose intensity above the standard dose level (60 mg/m2 for doxorubicin and 90 mg/m2 for epidoxorubicin) in MBC, does not significantly improve outcome and should not be used outside clinical trials. There is no strong evidence that patients with MBC could benefit from aggressive polychemotherapy compared with single-agent treatment with anthracyclines or mitoxantrone. There is statistically significant data that longer treatment improves the duration of responses and the TTP but not an overall survival except in one study. Generally, the toxicities increased with the duration of treatment. The overall efficacy of mitoxantrone appears to be slightly lower than for either doxorubicin or epirubicin whether compared as single agents or in combination with other drugs. This observation has not been made consistently in all trials. The risk of hematologic and cardiotoxic side effects appears to be less common for mitoxantrone than for doxorubicin and epirubicin. The choice of chemotherapy for MBC should be based on tolerability, quality of life, prior treatments, and the patient's own opinion. The possibility of participating to the clinical studies has to be given to the very well-informed patients.