Gemcitabine and targeted therapy in metastatic breast cancer.

Gemcitabine, a new cytotoxic nucleoside analog, has demonstrable single-agent antitumor activity in metastatic breast cancer. Recently, nearly 20 phase II clinical trials of gemcitabine alone or as part of combination therapy have confirmed its role in this disease. As a single agent, gemcitabine leads to response rates ranging from 16% to 37% in either first-line and/or refractory settings. Combined with platinum, taxanes, vinorelbine, and anthracyclines as doublets or triplets, response rates in the range of 50% to 80% have been reported in small phase II clinical trials. The relatively mild toxicity profile of gemcitabine makes it an attractive agent to evaluate in combination with targeted drugs such as trastuzumab, tyrosine kinase inhibitors, and angiogenesis inhibitors, among others. In this review we summarize current available data of gemcitabine in the management of metastatic breast cancer, and provide a perspective of gemcitabine in future clinical research for management of this disease.