Did I tell you about my friend's mom? I feel bad because my first thought when I heard she has cancer was that I can't make cancer jokes around him anymore.
Well, at least that sounds somewhat compassionate.
My thought process was that I wanted to make my friend feel better by telling him really bad jokes made up of cancer terms.
While you may want to help your friend deal with his mom having cancer, making jokes about cancer is the wrong way to go about it. Just be there for your friend and listen to him.
I feel that if I stop making cancer jokes then I'm not being true to myself.
Showing compassion for your friend is more important than being yourself right now. Some people use humor to assuage their grief; for most others, it's too soon. You know your friend -- act accordingly.