It might not actually be cancer too.... My lovely Dad died of mesothelioma - the cancer that comes after asbestosis and there is no sign that it's there until it's coated most of your internal organs - how long you live for depends on which organs it coats first... There is no cure for that, he had radiotherapy to try to take away some of the pain, but chemo etc doesn't/didn't work back then. I'd not want anyone to die the death that he did.
My brother in law passed away 3 months before my Dad and he was 2 years younger than me and had 2 small babies... He died of leukemia. He'd had it once and beaten it and it came back much more aggressively.
Both these men fought every single day to live...

Why have you given up?