Any affection is usually one way i.e. I cuddle into her. She occasionally slips her hand into mine but that’s about it. Without intimacy, there’ll be very little else (she wouldn’t dream of spontaneously giving me a proper kiss).
This is because she knows you would interpret it as a come-on and she does not want to be a cock-teaser. It is not because she does not care about you. She knows what you want; she knows what she feels she cannot do and she is being honest rather than pretending.
Sexual incompatibility is a major problem in many partnerships, especially as we age; but you have the double/triple whammy of cancer and of HRT not being an option.
The fact that so many women only find sex interesting after the menopause by having HRT indicates the primal nature of the problem - women's libido declines after a certain age as they have fulfilled their reproductive imperative/used up any decent eggs and nature runs their hormones down. Men are different. The survival of the species needs them to go on "putting it about."
If she were to just go through the motions for your sake then you would (I hope) find that unacceptable. What is she to do?
I do not think there is any simple solution to your difficulty. In her situation it is like having your libido surgically excised - it is not as if it is there in the background waiting to be awoken. That ship has sailed.
Maybe you could agree that you would "see to yourself" but to have as much intimate contact as possible. As long as she feels that initiating loving contact with you will lead to something she cannot participate in, you will both lose love and affection and warmth as well as the physical act of sex. That is two losses when there only needs to be one. If she knows for sure that she can show you affection without you jumping her, then at least you can share some love together. I am sure this is what she wants, but she can only avoid the impossible by shutting that down too. At least try and find a way where you can still share love.
The "seeing to yourself" option is far from ideal - but what you have now is even worse it seems to me: no sex and alienation.
It is worth remembering that her motivation to do anything about the sexual side of your relationship will be very low - she has faced a life-threatening illness which makes her think about what she wants to do/not do with the rest of her life. There is nothing medically that can be done with her history, so there is no point in her going to the doc. So she too is in a Catch 22. She loves you but knows you want something from her that she cannot give.
I wish you both well with this problem - but remember there are no easy answers and that her failure to engage sexually with you does not mean she does not love you and value your life together.