LGPA - Mass noticed in mouth and sore appeared on the outside in the cheek area

My mum has an LGPA, originally found around 30 years ago, but not identified as anything serious and therefore not treated. Some years later purely by chance, her GP who specialised in ENT, noticed the lump, which was across her soft and hard pallette, and sent her for investigations. A number of ops followed, the site didn't heal and eventually mum was referred to Oncology in Leeds, where she had further but more radical surgery followed by 4 weeks of radium treatment. This was around 10 years ago. Mum was left with a hole in the roof of her mouth, most of the right cheeck bone, and som eof the right lower eye socket removed. She was fitted for a pallette, which has been refitted a number of times as her jaw is shrinking. Mum has regular specialist apts but has had no investigations since a PET scan around 5 years ago, when she was told that the cancer was now attached to her sinus at the back of her head, close to the brain. Late last year, mum noticed a mass in her mouth which has been growing at some rate. Specialist said they couldn't do anything. Around Xmas a small sore appeared on the outside, in the cheeck crease, which is now a mass of what looks like abcesses, but coul dbe ulceration, yet still she is told nothing can be done. My question? Surely there must be more that can be done to help? Sorry - a bit long winded