Hi Anon,
Not off the top of my head. There could be a tumor pressing on the part of the brain that dictates how the body perceives temperature, or if it's something like shaved ice, maybe the texture is appealing. Another possibility is that if they've had radiation treatments, sometimes they can tear up the saliva glands and they don't work properly, and that's their way of keeping their mouth/throat moist.
As to the meat...it could be medication related, or just a changing preference. It's hard to say with brain cancer because the brain runs everything and you just don't know how any changes will manifest.
I hope this was of some help to you.
Jim