Disease Site Group Consensus Process
In the context of current clinical practice, the Breast Cancer Disease Site Group (DSG) discussed the evidence surrounding the role of the taxanes in the treatment of women with metastatic breast cancer. The DSG agreed that the primary goal for treatment in this population is to achieve the longest survival with the best quality of life, using a treatment with acceptable toxicity. There is very little reported difference in overall survival among the standard chemotherapeutic drugs available for patients with metastatic breast cancer. While there is some variability, it is now conventional practice to commence therapy with an anthracycline-containing regimen, followed by a taxane as a single agent as second-line treatment. Third-line treatment usually consists of capecitabine or vinorelbine. As they have in the past, members of the DSG acknowledge that there is a role for innovative treatments and investigational agents at each point in this treatment algorithm, including the introduction of investigational new drugs in patients who are chemotherapy-naive.
The DSG considered the evidence regarding the use of a taxane (either alone or in combination with other agents) in the first-line setting, where anthracycline-based chemotherapy would ordinarily be considered. Members of the DSG acknowledged that a survival advantage for a taxane-based regimen over a standard anthracycline-based regimen has not yet been demonstrated. However, it was also pointed out that significant increases in response rates and time to progression have been demonstrated in this setting, when a taxane is used alone or in combination with an anthracycline. In particular patients, those with aggressive, symptomatic disease, a taxane-based combination in the first-line setting might offer a higher probability of response, and by inference, a relief of symptoms. In patients with particularly aggressive, rapidly progressing disease, a taxane-based treatment in the first-line setting might be the preferred choice to provoke a more rapid response. However, this argument could not be resolved with the currently available data, because time to response is rarely reported in trial results. After considering these issues, the DSG members agreed that in the first-line setting, either paclitaxel or docetaxel could be considered as reasonable treatment options for patients with metastatic breast cancer who receive multi-agent chemotherapy. The DSG members recommended that the choice should be offered to patients who are fully informed about the harms and benefits associated with each drug or drug combination, especially as cardiotoxicity and febrile neutropenia remain of concern.
The DSG also considered the evidence regarding the effectiveness of docetaxel over paclitaxel. Docetaxel appears to be more effective than paclitaxel, based on indirect comparisons, but published results of an ongoing trial directly comparing the two drugs are not yet available.