Hi, @dorisena - just wanted to point out a Mayo Clinic article on causes of cancer https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/cancer-causes/art-20044714 that might be of interest to you. It offers this information on a cancer causation myth related to sugar:
Myth: People with cancer shouldn't eat sugar, since it can cause cancer to grow faster.
Fact: Sugar doesn't make cancer grow faster. All cells, including cancer cells, depend on blood sugar (glucose) for energy. But giving more sugar to cancer cells doesn't speed their growth. Likewise, depriving cancer cells of sugar doesn't slow their growth.
This misconception may be based in part on a misunderstanding of positron emission tomography (PET) scans, which use a small amount of radioactive tracer — typically a form of glucose. All tissues in your body absorb some of this tracer, but tissues that are using more energy — including cancer cells — absorb greater amounts. For this reason, some people have concluded that cancer cells grow faster on sugar. But this isn't true.
However, there is some evidence that consuming large amounts of sugar is associated with an increased risk of certain cancers, including esophageal cancer. It can also lead to weight gain and increase the risk of obesity and diabetes, which may increase the risk of cancer.
My 55 year old friend died of metastatic breast cancer that went to the brain. Her oncologist told her not to eat any sugar because it feeds cancer. She complied and perhaps lived longer...but sadly did eventually die...
This TED Talk by Dr William Li on Angiogenesis, Can We Starve Cancer is very informative concerning the relationship between what we eat and cancer. https://www.ted.com/talks/william_li?language=en