As opposed to the good ones?
Regardless...
I'm going to make this really simple for you, cos well y'know, I have to.
Just because you've lost family and friends to cancer and are OK with jokes about it, doesn't mean all people who've been in a similarly unfortunate position should therefore be ok with it also. In fact, some people are NOT OK with it.
You're not a spokesperson for cancer sufferers Dreamy, and you cannot generalise on behalf of them. Cos well you see, different people have different emotional reactions.