Taking hormones after breast cancer can hurt the joints.

Following my operation, chemotherapy, radiotherapy and herceptin I was told to take Tamoxifen tablets which I did for 5 years. My oncologist then changed my medication to another hormone, saying it would give me the best chance of avoiding a return of cancer and I started to take letrozole. The problem with taking this drug is that it can make any arthritis and joint problems worse, which I soon found out, but I decided to try and persevere with it as I wanted the best chance I could of keeping the cancer at bay. I am now, unfortunately, at the point where walking is very painful and I cannot walk very far at all,but then again I could not walk all that far previously so would this have happened naturally, or is the increase in pain and the subsequent decrease in mobility due to the medication alone, or to the worsening arthritis, or both? I am going to my GP today to ask some questions and to request a referal to a rheumatologist for a second opinion as to be quite honest I do not want to stop taking the drug only to find my pain and mobility stay the same, and the worse happens which would be the return of the cancer. I do not know if the pain and loss of mobility is solely due to the medication or whether it is partly due to the worsening of my arthritis and degenerative disease, or whether it is actually making the arthritis and degenerative disease worse! I am very reluctant to stop taking the medication, even though I now have so much more pain, because I am quite frankly scared that if I stop taking it the cancer will return and that is what I am the most afraid of, it terrifies me. I am going to have to make some difficult decisions, or perhaps I will just stay as I am.