Effectiveness of numerous regimens have been tested in advanced breast cancer but since these trials were able to compare only a few regimens, it was very difficult for researchers and clinicians to determine the relative merits of the individual regimens.

A systematic review, done by the researchers from the University of Ioannina School of Medicine in Greece in order to determine how regimens compared with one another, showed that non-hormonal treatment regimens, including anthracycline-based regimens and taxanes, improve overall survival in women with advanced breast cancer.

The researchers performed a meta-analysis of 128 clinical trials and included 148 comparisons between regimens. The whole review included 26,031 women with advanced breast cancer. For the base line for comparison, they used single-agent chemotherapy with old non-anthracycline drugs.

The use of anthracycline regimens led to a 22 % relative risk reduction in overall mortality as compared with older single agent chemotherapy. Single drug taxane treatment led to a similar relative risk reduction of 33%, while the combination of a taxane with capecitabine or gemcitabine led to a 51 % relative risk reduction over the single agent chemotherapy. Most of the regimens appeared to have similar efficacy when used in women who had not been previously treated and in women who had had prior therapy.

The meta-analysis performed show major progress achieved in the treatment of advanced breast cancer with non-hormonal systemic treatment in the last 35 years. A few regimens have shown magnificent results in their effectiveness.

Due to the unavailability of the standard comparators, there is still no consensus regarding the best dosage, timing, sequence or combination of therapies for the treatment of metastatic breast cancer and this is why the work of the Greek scientists is so important.

Since the meta-analysis showed that many of the regimens have similar relative effectiveness in previously-untreated and -treated patients, no clear order of use will be determined and and no alternation in the clinical practice will come out of it.
Other considerations, such as toxicity, will continue to help drive the choice of regimen for individual therapy.

However, the analyses does show that the survival of women diagnosed with advanced breast cancer has improved because of more active systemic chemotherapy and targeted therapy. This provides 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.