Just a thought..
Seems like info keeps coming out about the evolution of tumors and how adding or withdrawing certain agents for various time periods can resensitize tumors to certain agents. I sometimes wonder if a constantly rotating series of chemos could keep the tumor from having enough time to develop resistance. You know..instead of continuous left jabs, ultimate fighting. Ok..goofy analogy.
Have you investigated directed liver therapies like SIR spheres, LC beads, intra arterial chemo or :
http://her2support.org/vbulletin/showthread.php?t=37938