If you are already infected with the spirochete, chemo does weaken your body and it's defenses.
Chemo is just plain bad news, so many die from it before the cancer would have done them in. (but the cancer always gets the blame).
The only value I see with chemo (other than enriching big pharm) is it is an excellent anti-inflammatory which inadvertently keeps dangerous brain edemas under control. (something most oncologists don't know, the brain edemas can kill and the cancer gets the blame)