I used cold pressed oil made from biodynamic marijuana during my 20 weeks of chemo.
Grown by a friend who has had rheumatoid arthritis for 20 years she has grown hers specifically to counter the effects of the steroids she must take.
She showed me how, without any heat involved (which interferes with the plant's botanics) you extract a black tar like substance, which you then mix with manuka honey to make it palatable.
I didn't take it to shrink my tumors but to counter the effects of chemo (which comes with a lot of catabolic steroids). It made chemo more tolerable. It kept me 'grounded' and reduced my anxiety to manageable levels.
It's very expensive but was worth every penny. I'm sure it's not for everyone but it certainly worked for me.