I learned one of my early lessons on steroids from my wife. She has GBM. Brain swelling is just not an option. They gave her Dexamethasone for the surgery and through radiation and chemo. Then they needed her to taper off to do immunotherapy treatments. They told us as close to off as she could get. I quickly found out how difficult that might be. We could only get down to 1mg which is about the equivalent of 5.5 prednisone. Otherwise your defeating the purpose of immuno drugs. In our case avastin and keytruda. I think we did 3 infusions and then stopped due to an infection. Was the infection from the steroid use or the immuno drugs or something else. Not sure. The immuno drugs have the risk of increasing infections. This can be made much more serious by steroids. The infection was the game changer in her cancer journey. We never fully recovered. I ended up with PMR she did not have it . I cant imagine your having to deal with cancer and the PMR. I dont have an answer to give you. But in my wifes case, she was not a candidate for any more immuno treatments.