Why would he give a fuck about support from random douchebags on the internet? If he has no friends or family to support him, maybe dying isn't such a bad thing anyway. I'd be living the SHIT out of the rest of my short life instead of whining on the internet about it.
I don't know if he cares that much, or if it's just a thing his friend wanted to do. Ovens mate, it's easy to say that you would live the shit out of your life, but if you had a disease that makes your insides rot then you might not be too energetic when you get up. And chemo's usually have bad effects like nausea, being tired, etc. I would probably try to make the most out of my remaining life, yeah, but if he wants to play Toribash then that's his choice. You should keep in mind that he's not asking for gifts or anything, he's just asking if people could put 2 words in their signatures so that the cancer-guy might feel better.
I can't say for sure now whether or not it's fake, so I won't go there. Also, keep in mind that it's GlacierMan and not DecoleMan who made the thread.