I believe Chemo is an anti-fungual treatment.
It has a bag drawback though, it works too fast. You need lots of sulfur in your gut when on chemo, lots! but as you'll see with me and others on the forum too much systemic sulfur can cause a healing crisis and make you really sick. Sounds like chemo doesn't it. It is the same thing!
I always strictly control any systemic sulfur like SAM-E, and N-a-cistine (NAC). On my tummeric I can eat a ton of it, and chlorella seems less systemic also. Also melatonine seems tollerable in huge amounts, thats staring to be used in other "get well" groups, they are catching on fast! Im not sure about the differences in the sulfurs, but there is some kind of difference. If I get too much DMSO, like yesterday I feel like I'm going to die, so today I stuck to tummeric curcumin mostly and Im getting better.
I would get my friend started on the MMS solutions as fast as I could and do my best to avoid chemo if at all possible. Cut out all his sugar. (Id take turpentine and anti-fungauls late at night (I do that now), I'd eat some dark meat chicken at each meal, not much, (there are reports of this helping, I know it helps me, and its more than the sulfur in the meat) and Id start on the MMS starting protocols asap.
When the doctor initiates chemo it kills off all your sequestering bacteria, all that bacteria uses Hydrogen sulfite (not sulfate, sulfate is good. Sulfite is not good for your body, its a last resort). Your body uses and grows it just (like a fungus), thats why we get tumors too. You body figures out really fast when you are recirculating metal and its freaks out and starts growing this hydrogen sulfite sequestering bacteria, its one of the stages before what is called cancer. That Sulfite in that bacteria is often the only thing keeping you alive at that point. You want to be able to catch and excrete all that toxic load (Toxic heavy metals plastics. etc) and not let it recirculate. Read my post called "Sulfur" in alternative treatments.
Good luck to you and your friend!