Mushrooms! My best recommendations would be to try extracts of Turkey-tail, Shiitake, Maitake, and/or Chaga (and maybe Lion's Mane for lungs). 'The Fungal Pharmacy, ' by Robert Rogers is a good book on medicinal mushrooms and which mushrooms are good for which cancers/illness.
This recommendation would be in addition to diety changes, primarily eliminating sugar and processed foods from the diet. My wife had stage 3 Hodgkins lymphoma in 1997. She was cancer free in 3 months after following Macrobiotic recommendations and 1/2 the prescribed chemo. Shiitakes were part of the dietary recommendations (2x/week) and lead me down the medicinal mushroom rabbit hole.
Mushrooms have ways of stimulating the immune system and tackling tumors. The way they do this is not yet fully understood, but the research continues. Maybe mushrooms can be of some help to you... my wife is doing fine still.
~Rodney Webb