Had invasive ductal carcinoma 6 years ago. Took tamoxifen for 2 1/2 years, followed by aromasin for two years. Aromasin, like arimidex, is an aromatise inhibitor. My back pain, ankle pain, joint pain, got so bad, that I couldn't get out of bed. Stopped taking aromasin after 2 years, but still have long term side effects. Back pain still exists. Orthopedic docs want to do fusion, but finally found cancer specialist with rehab background that told me I didn't need surgery, but rather put me on a regiment of steroids, anti-inflammatory drugs, along with traction. Some help, but daily swimming seems to be my best friend. For more info on all the aromatise inhibitors, I suggest you go to breastcanceraction.org for their report on the long term side effects of these drugs. You are not alone; women across the United States are complaining about the side effects of these drugs. Hope this has been helpfuol.