Are you aware of what an anology is? Have you ever exaggerated or used analogies to make a point?
Lol, don't go so far as to hope for death by fridge, but comparing dude to a terminal illness is cool. Got it.
Cancer is a terminal illness, yes, but the more technical term is a harmful entity that slowly expands to other areas by its own volition and at the expense of everything around it. Rust along a car's wheel well, for instance, is also considered cancerous as it spreads akin to a cancer. Are you also going to go to mechanic forums and blast mechanics for using that verbiage?
What he said was not some societally accepted phrase. He literally specified a manner in which he wanted someone to die. If you can't find the discrepancy between the two, that's sad.