Katie,
I have the same pathology, her2+++, er-, pr+10%, and didn't know it was rare??!! I haven't heard of Ki-67--but will look into it.
My onc has me on tamoxifen, she says that new studies show that it can give a slight edge with even small amounts of hormone receptors. I'm going for the edge. Although from what I've been reading it probably isn't even working, my side effects are minimal. If your hot flashes were bad, according to this article it may mean it was working...
http://abcnews.go.com/Health/CancerP...=4009620&page=
Amy