Hi there. I'm sorry to hear about
your breast cancer, and I hope everything works out well for you. I had to stop taking orencia, another biologic, for a while due to a skin cancer (and healing from the skin cancer surgery). It took a few weeks for the inflammation to build back up in my system (5-6 weeks), and once it did, it was pretty difficult for a while. That being said, your rheumatologist can prescribe other things (e.g., prednisone) to help bridge you through the radiation until you can start taking enbrel again. I did not take anything except the methotrexate (which I did NOT have to stop taking for the skin cancer), and tramadol. Maybe you should just adjust your routine until you can finish up the radiation therapy and re-start the enbrel. It does take a while, though, for inflammation to start building back up in your system after you stop taking one of these drugs.
Best,
Elcamino