I am not a doctor. I've never had cancer, though I've had numerous close to me diagnosed and have actually studied it quite a bit. So with Jimmy's Crap on the Jaminets fest going on over on his blog, lots of opinions on diet for cancer, ketogenic specifically, and Paul's "dangerous" recommendations are being bantied about. I would be remiss if I didn't point out that Shou-Ching Jaminet is a cancer researcher! But I guess she's only responsible for Paul's white rice consumption, and has no bearing on Paul-the-astrophysicist's understanding of molecular biology. Yeauh right. :-(
I remain ambivalent that diet can be used to "starve" cancer. The signalling molecule angle doesn't sway me either, because, the big thing about cancer cells is that they have lost their signaling. They have gone rogue and are as foreign to your own body as bacterial cells. Indeed one of the knocks on in vitro human cell cultures is that they are derived from cancers. Why? Because bacteria replicate because that's what they do. But the cells of multicellular organisms can be put in nutrient rich media and they will NOT divide and grow. They (may) survive for a while and die. And so all higher organism tissue cultures require establishment of "immortal" cell lines that divide and multiply in a dish. (Not all in vitro experiments use these, they use isolated cells cultured and exposed to various stimuli ... such experiments are short-lived!) The phenotype of these cell lines is also variable. For my PhD thesis I was going to look at bone titanium interactions and did a fare amount of research before selecting a particular human cell line. Bone physiology is complicated and not all bone cell lines express the matrix-building characteristic, etc. Indeed often "functional" cells will de-differentiate in culture and stop expressing their identifying phenotype.
Chemotherapy basically works by intervening in cell growth/proliferation mechanisms. Basically to kill the cancer before it kills you. This is why your hair falls out, because hair follicle cells are rapid proliferators. Radiation is stressful on the body. Newer therapies are harnessing the power of your immune system. ALL are benefitted by the rest of you being as nourished and able to fight the *bad* as possible.
If I were diagnosed with cancer, I would provide my body with the most healthful, least stressful diet possible so the rest of me will live and be stronger. You're under enough stress, why add more with a diet that stresses the body? That would include at least 100g-150g starch carbs. Folks the cancer cells are going to take the nutrition they will whether you add it directly in the diet or not.