Hi,
my husband has crohns and while he hopefully does not have cancer at the moment (waiting on results of biopsy) we do have a family knowledge of cancer (I was diagnosed with esophageal cancer 3 years ago and am a type 1 diabetic, had graves when I was a child and am now underactive) I would be considered imminocompromised as a result - they did tailor my treatment to match my conditions (was 32 at diagnosis and wanted to have a baby at some stage in the future). Am in my second trimester of my pregnancy now.
Chemo is never easy but your brother can get through this with your love and support and the wonderful oncology staff.
I hope that this helps,
Best wishes,
Aoife