I have been on most that you have named, carbo/taxol, doxil, gemzar, topotecan,
and now avastin/abraxane. I was dx with mets to
the liver and all of these drugs have helped at least a little bit. They just don't work long enough, and when one stops working, it is time to move on to something else.
I think that the best thing for you to do is to ask your Dr what he thinks would be a good course of action for you.