Sounds like you are trying to kill off some white blood cells because they are cancerous.

USC did a study and found that 3 days of fasting kills white blood cells. After the fast, they come back in greater numbers and stronger, and they tend to rebuild the immune system (to the extend that WBC's are part of that). Might this mean they would also be healthier cells? I don't think they looked at that.

https://news.usc.edu/63669/fasting-triggers-stem-cell-regeneration-of-damaged-old-immune-system/

Otto Warburg showed more than 100 years ago that most cancer tumor cells survive on glucose. Deprive them of glucose (carbohydrates), and they die.

https://killcancercells.com/cancer-researchers/warburg/

Today's mainstream medicine discounts Warburg's work due to the fact that it does not work on ALL cancers. However, Thomas Seyfried has shown that these other cancer cells, including the blood cancers, can survive on glucose OR glutamine (an amino acid found in most foods). So, Warburg was not wrong, but he did not have the complete picture.

Once I found out about that I suspected that fasting could work, since that would deprive the body of both glucose and glutamine.

Now, Seyfried seems to be taking that approach, as well.

https://thequantifiedbody.net/water-fasts-as-a-potential-tactic-to-beat-cancer/

I also came across this NIH paper that discusses this in more detail:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4493566/

If I ever got cancer again, that is the approach I would take. Of course, getting an older person to go along with it is a different discussion -- nevermind the doctor who has been indoctrinated in the wrong approach.

Best of luck.