I did 5 years and then did a Breast Cancer Index test that said there was no further benefit with extending meds to 7 or 10 years. I would have been comfortable doing 7, which some studies says is of the same benefit as 10, but I had osteoporosis before cancer and am prioritizing bone meds right now. One oncologist says I can do two years more of Femara in a year if I so choose.