Hi Sue: That's kind of like asking "How long does it take to drive your car?" What kind of car? How fast are you going? Where are you going?   Breast cancer treatment can take, at a minimum, and not counting post-treatment drug therapy, about 1 month from diagnosis to finish. That woould be if you had a quick lumpectomy, and one week of radiation via MammoSite. This is fairly unrealistic. In general, I think it's safe to say active breast cancer treatment can take anywhere from 2 months to 9 months; or longer if you have more serious cancer. It can also take the rest of your life, if you count hormone drugs. Hope this helps - PJH