I meditated on this to see if I would get a picture of a plant and came up with cleavers. It's a lymph cleanser, which I needed after surgery, staph infection and radiation because my lymph system had shut down. I got very cloggy, according to a physical therapist who specialized in lymph problems. It's as important as blood to clean and carry the bad cells away.
I got scared too after a year of going through the whole process, felt good for a while, then got the itchy feeling in my armpit, and a feeling of heat (burning out infection?) in my breast that had been affected. I was lucky to have a Tibetan doctor around, and his herbal medications helped, but also I took the cleavers, and somehow olive oil on my skin really helped. It's supposed to go down through layers of skin to heal. I pictured it doing so.
I have to say though that I gave up on the idea of fighting cancer. I seemed to really improve when I started thinking of healthy cells getting healthier instead of bad cells going away. And I set longterm loving goals of having loving friends around me in the country with all these plants around in the future, and including my 7-year-old granddaughter in the picture, but I envisioned her in her 30s!
Would it help your friend to try to connect with a plant, any plant, to get very familiar with it, and ask it for advice. Those homeopatic pills original from plant material.
I send healing and calming thoughts to your friend.