You know what's worse than cancer? Death. I mean, you may or may not die from cancer, but people die when they are killed... yet, [Death] seems to be a perfectly acceptable difficulty name. I didn't see anyone fling shit when maps got ranked with that as a difficulty name, at least.
Do you know why? Because it's a fucking difficulty name. It's a terribly abstract and unintuitive concept, but the surprising truth is, a difficulty name isn't going to kill you, or give you cancer, or hurt you in any other way for that matter. It is a terrible thing--this trend of people playing the "defenders of justice," making a scene out of fighting phantom enemies for a nebulous moral cause.
If you don't take offense to the difficulty name [Insane], which, by the reasoning I've witnessed in this thread, would be interpreted as a hideous mockery of the mentally ill, I don't see why you should take offense to cancer. After all, they both serve the same purpose: terms for medical phenomena whose meanings illuminate the design of a map at a glance.