(A post intended to be sympathetic to both the OP and one of the thread's commentators - himself a cancer sufferer - has been removed. There was a "joke" bit (presumably the reason for the removal) based on "carpe diem", but the new intake of moderators obviously doesn't do ancient forrin'. I would, however, have expected both Nailit and Peter Pedant to have understood my intent.).
My first wife died at the age of thirty-six after a "successful" operation to remove a tumour in her kidney. Her six-month course of chemo at the Royal Marsden (Surrey one) was stopped after three months. Why? Oh, forgot to tell you, the tumour had penetrated the renal artery, was vigorous and had penetrated bone and lung. Thank you, doctor. She died two months later.
This is not an uncommon experience except that I saw my wife rather than, say, a parent die in a bad way.
I do not make light of cancer. Nor of those who suffer from it. Nor of those who observe the suffering.
Cancer is not a single beast and all cases vary. I hope Nailit's mother has a peaceful end.