Freaking out delayed treatment

I was diagnosed  with Occult breast cancer OR and HER2 negative locally advanced with 6cm metastasis in the axilla node and 4 smaller ones. I also have rheumatoid arthritis. My consultant and oncologist want to start me on CDK4 along with Letrozole but I take immune suppressants and inject Methotrexate weekly for my rheumatoid.  My treatment has been delayed as scans showed other concerns so have had further tests and thankfully all good.Does CDK4 suppress the immune system?  Some days I feel quite low.

Any advice on questions to ask the drs before I start my treatment? 

Sounds like you’ve had a rollercoaster ride . I’m not sure about how those particular drugs impact on the immune system but you could maybe ask advice about this in the ask the Nurses section of the forum ? There are quite a few people on this treatment on the forum so hopefully someone will be along soon with knowledge of this .Hope all goes ok with your treatment , lots of support here if you need it x