Experts please, going holistic after chemo

I would like opinions from those who know. When dealing with a male patient of about 67 years, who has been on oral chemo program for 1 year for leukemia, how much damage has this chemo done to his innate ability to recover if put on a full natural cure program? When I say "full program", I mean the works, gerson type therapy with raw diet, liver cleanses, anti cancer herbs, o2 therapy, and organ support herbs based on iridology analysis. I have little knowledge of Luekemia or the type of chemo use that acompanies it. For the moment all I know is he's been taking "oral" chemo for a year and he has that "smell". I recently guided my step father to full cure of prostate cancer, I would like to help this guy, he's open to trying but I want to know what his chances are. Only recently he has been quite active, I don't see him as being terribly weak yet.