Thalidomide has been used in oncology trials because of its anti-angiogenesis property. Other drugs are used - of course it all depends on the cell type of the tumour.
You have a good 'handle' on this, if I can be so bold.
In my opinion, the overriding crux of the tumour/glucose debate, must rest with the knowledge that all rapidly dividing cells have an increased glucose utilisation, but, the amount is likely to be a minuscule amount in comparison to a 4g teaspoon of glucose.