As far as treatment I believe that your Sister's Oncologist would be your best source of information. Many factors must be considered in formulatng a treatment program and only the Dr.s in charge of the case would have all the necessary information to answer the questions you have. Survival rate also depends on the above mentioned factors as well as the treatment plan that is followed. Regards ....
I totally agree with the reply you got from "japdip". But I'm a 3 yr survivor of stage IIIA, breast cancer with positive nodes and have some information that might be helpful for you. I sent you a private message so please check your inbox when you have a chance.
Its great that your sister is blessed to have you supporting her and looking out for her. That is so important while going through breast cancer. Good luck to you both.