Expanding options in breast cancer

In metastatic breast cancer, docetaxel is the only drug to have shown superior activity to doxorubicin [objective response rates (ORRs) 48 versus 33%] by direct comparison in a randomized trial. Importantly, this greater activity was accompanied by a lower risk of cardiotoxicity. Docetaxel has also proved superior to various combination regimens in patients who had previously failed anthracyclines. In the comparison versus mitomycin C plus vinblastine, survival was significantly prolonged in the docetaxel arm. The combination of paclitaxel with doxorubicin has achieved remarkably high rates of response. However, the combination is cardiotoxic (with the highest response rates reporting an incidence of clinical congestive heart failure in the region of 18%). In comparison, the combination of docetaxel with doxorubicin, while also highly active (ORR > 70%), is relatively non-cardiotoxic (with only one case of clinical congestive heart failure in 96 patients treated). Given that docetaxel appears to be the most active single agent in metastatic breast cancer, there is a compelling case for the drug to be evaluated in the adjuvant setting and such studies are ongoing.