You can change inter/intra cellular ph quickly, why wouldn't you against a progressing illness like cancer?
Surely, get started on diet,..I love juicing, start ph therapy diets,...just help them out early with strong buffereing agents as this can be done today, not tomorrow.
Besides, the ph of your urine has nothing to do with the ph inside a cancer cell, (well, almost nothing.)
Early intervention is a common link to successfull outcomes. So why delay what your goal is?
Don't give a disease like cancer any head start, don't give it a thing don't give it crap! Waiting one day doesn't seem logical to me, especially if you don't have to give up that day to cancer!
Side note*
I have seen lots of cancer patients go to the grave on a special diets.