I saw this in the New Scientist yesterday: Cancer's sweet tooth becomes a target
It is intersesting stuff.
Most of these efforts stem from an observation dating back to the 1930s - that cancer cells generate energy via glycolysis. This is different to the way cells normally make energy, through aerobic respiration in specialised chambers called mitochondria. Ordinary cells do use glycolysis but only if they are short of oxygen, as it is hugely inefficient, gobbling up large amounts of glucose for very little energy .
The focus is all on drugs though rather than diet