Mum recently been diagnosed with t4 scc mouth cancer

My mum has recently been diagnosed with t4 scc mouth cancer that has spread to her lymph nodes and her jaw we have been told an operation isn't a option waiting to go back this week to see what the doctors have decided the best treatment will be I'm worried as she 75 and very weak as she has lost alot of weight was hoping to get some advise from people that have gone through the same and came out cancer free