How long to treat metastatic breast cancer.

It is common practice to continue treating metastatic breast cancer patients as long as responses are expected. NCCN recommends singel agents mostly but also a few combinations for second line.  However, there is little evidence to support this practice after the first few lines. In any case, Herceptin is now being continued in a third consecutive regimen, which is not supported by guidelines or literature and is considered experimental. NCCN on p. MS-43 recommends continuing Herceptin into consecutive line of therapy but says that the duration of that is unknown. It also says on MS-2that continuation of chemotherapy past third line is not recommended and only supportive care should be given.