There are many non-conventional treatment protocols for cancer therapy. These range from diets to supplements and herbs. It has been well documented to decrease sugar levels in patients with cancer by using insulin and this will regress the tumor. This is done using Insulin Provocative Therapy (IPT). This has been done on the west coast of the United States and in Europe.
There has been reports of 'fasting' for certain types of cancer. I have seen it work for some patients but is not suitable for all. As published in a peer review cancer journal, BMC Cancer, "Evidence indicates that 'short term fasting' protects healthy cells against side effects of chemotherapy and makes cancer more vulnerable to it."
We know that cancer is fueled by glucose. This is the reason why insulin provocative therapy works in reducing glucose thus killing cancer. In the same vein, interim fasting can produce the same results.