Docetaxel is more effective than paclitaxel in reducing tumor size and improving survival in women with metastatic breast cancer, according to a presentation at the European Conference of Clinical Oncology.

The phase III trial enrolled 449 women (premenopausal or postmenopausal) with metastatic or locally advanced breast cancer who were randomized to docetaxel or paclitaxel.

Peter M. Ravdin, MD, PhD, principal investigator, said “In all groups, there was a trend for Taxotere [docetaxel] to be a better drug.” Patients on docetaxel showed greater tumor shrinkage and tended to live longer (average 15.4 months versus 12.7 months for paclitaxel patients).

“Although that’s a modest difference, for those people who lived longer it was important,” Ravdin said. “And when a therapy demonstrates a survival advantage compared to another therapy for advanced metastatic breast cancer, that advantage often is translated into an advantage for patients with early breast cancer, where adjuvant therapies have curative potential.”

Although clinical outcomes were improved with docetaxel, the drug was associated with more side effects, including leucopenia and leukopenia-associated infection. Of the women in the docetaxel arm, 14 percent had fever while leukopenic compared with only 2 percent of those treated with paclitaxel. Ravdin commented, “Taxotere [docetaxel] was the more effective therapy, but it was also the therapy that carried more risk.”

A trial comparing the 2 drugs is being conducted in patients with early breast cancer.