Nonhormonal agents improve survival in metastatic breast cancer

MedWire News: The findings of a systematic review show that nonhormonal treatment regimens including anthracycline-based regimens and taxanes, have improved overall survival in women with metastatic or recurrent inoperable breast cancer over the last 35 years.

Previous studies have tested numerous regimens in advanced breast cancer; however, each of the trials has compared only a few regimens, making it difficult for researchers and clinicians to know the relative merit of the individual regimens.

To redress this, John Ioannidis (University of Ioannina School of Medicine, Greece) and colleagues performed a meta-analysis of 128 clinical trials that included 148 comparisons between regimens. In all, 26,031 women with advanced breast cancer were included.

The investigators compared single-agent chemotherapy with old non-anthracycline drugs as the baseline for comparison within their meta-analysis.

They found that the use of anthracycline regimens led to a 22% relative risk reduction in overall mortality as compared with older single agent chemotherapy.

Taxane only treatment led to a similar relative risk reduction of 33%, the researchers report.

Most of the regimens appeared to have similar efficacy when used in women who had not previously been treated and in women who had received prior therapy.

“Several regimens have shown effectiveness, and for some of them, the treatment effects are practically indistinguishable in magnitude," the authors write in the Journal of the National Cancer Institute.

"Given that subsequent lines of treatment can confer similar relative benefits as the first-line setting, one can exploit the survival benefits conferred by several effective regimens used in sequential fashion."

In an accompanying editorial, Philippe Bedard and Martine Piccart-Gebhart of the Jules Bordet Institute in Brussels, Belgium, note that until now there has been no consensus regarding the best dosage, timing, sequence or combination of therapies for the treatment of metastatic breast cancer because standard comparators have not been available.

"This [present study] should provide hope to patients, investigators, industrial sponsors, and regulatory agencies alike that well-designed clinical trials with novel systemic therapies can further alter the natural history of this devastating disease."