I am also on Arimidex and due to go for my 4 year check up, 3 on arimidex, but last year i did ask my doc about the 5 year mark, she did say if this was your 5 year mark, then we would suggest stopping it, but as i had a few more years on it, that things may change, i'm not sure if Arimidex is still a new drug, and therefore even the doc doesn't know much about ongoing treatment with it, however i am due to go for my yearly check up next month, and am going to try and get a bit more information, i think your doc saying it is up to you, is a bit slack, as although the final decision is up to you, a bit more information on the continuing use of it, would be good to help make that decision. good luck and keep us posted on what you find out or decide. Take Care moira