I'm so sorry to hear that. My uncle has a cancerous brain tumour ATM and it's terminal he is in a hospice and cries alot as he knows he is going to die. It's so hard.
But all you can do is be there for them and support them. Hopefully your gran will get better! I suppose it's the word cancer that scares everyone so much as there is so
Much stigma attached to it. She is in the best possible care and the cancer doctors are so much help, if you need help with coping with cancer in the family there is help with Macmillan cancer etc online!
Keeping your grandma in my thoughts!
Big hugs!! Xx