In treating metastatic breast cancer, the answer is always "it depends".  After all, the goal of treatment is to keep the person in as good shape as possible for as long as possible, which is hopefully on their feet and active instead of suffering from side effects of the cancer (as in visceral...

Our approach is to continue chemotherapy until disease progression or unacceptable toxicities. This follows the generally accepted strategy used in breast cancer clinical trials. Initiation of endocrine therapy following progression is reasonable in patients who are no longer in visceral crisis.

Yes. When the overall visceral burden is lower after a few cycles of cytotoxic therapy, it’s best to switch. There is always the chance they may respond to a re-challenge in the future to chemotherapy. It also gives patients a chance to have a higher quality of life. 

If we choose chemotherapy as the initial therapy to address true visceral crisis, the chemotherapy drug should be continued until progression or unacceptable toxicity and this would be true for all agents except anthracyclines.  This recommendation is based on the accepted standard in clinical...

I would always be concerned about switching a successful therapy, no matter what the disease and circumstances. If there are toxicities, modify doses but a switch is a Russian Roulette mainly if the patient has been in visceral crisis. This is not the average patient which was on the trials