My Mam's cat Cleo (18y/o long haired blue), has been diagnosed with blood cancer and a large tumour on her bowel and stomach. She's lost 1/3 of her body weight over the last 4 weeks so we took her to the vets.
My Mam was very distressed so atm we don't have many details and I want to be sure that whatever is decided for Cleo, is the right decision. Cleo has stopped eating and is drinking very little.
I have a few questions for the vet (prognosis, treatment, success rate etc) but is there any thing else I should be asking? I am in the fortunate position of never having to have this conversation with a vet before

I know one of the options is for her to be put to sleep but unless it would be kinder to her to do so, I want to avoid that.