Okay, I'm going to chime in here because diet is something that I did a TON of research on.  We really believe that it is the reason that Zeus outlived his prognosis and I am so proud of the fact that our vet mentioned on several occasions how he didn't see the typical "cancer cachexia" (wasting of muscles that causes the sickly, sunken look in cancer patients).  Zeus never lost weight or looked sick at all, even at the end.  And NOT ONCE did he refuse to eat, until that very last day.

Because all research in humans and animals shows that cancer feeds on sugars (and carbs are easily broken down into simple sugars), you want to avoid sugar and carbs as much as possible.  Although I didn't buy into everything that Dr. Dressler recommended in his book, I did believe the high-protein diet theory because there is SO much science to support it.  Since I just couldn't do 100% cooked, we fed Zeus 1/2 kibble (Halo) and 1/2 home-cooked.  We did a variation of the cancer diet and replaced some of the hard-to-keep-on-hand fresh ingredients (like cottage cheese and turkey necks) with supplements.

Part of the cancer diet includes ground beef and beef liver, and there are very specific cooking instructions.  As they are both high in fat, to avoid stomach upset you should brown the beef VERY slowly in a lot of water and then drain well (I'm sure boiling it would be just as good).  As for the liver, it must be cut into very very small pieces (to allow more of the fat to escape so you don't have stomach upset) and boiled/simmered.  We would then pour it through a colander and rinse it to get the excess fat off.  The vegetables should be boiled until they are soft and then mushed up with a potato masher or blender.  This allows the dog to benefit from the nutrients more before it passes through their system.  The reason for this is because veggies are hard for a dog to digest fully before it passes.  In the wild, dogs would get their veggies through eating the stomach and other organs of the animal that it killed, which meant that the foods were already partially digested.  As for the oatmeal, don't use instant - use the kind that has to be cooked and use steel-cut or rolled oats (which basically means not-instant).  I know this is a really long answer, hope I didn't bore you to death!

From Dr. Dressler:

"Even dog lovers who feed their dog homemade food often include
carbohydrate-rich potatoes, peas, corn and carrots in their meals. The body
breaks these vegetables down very quickly into simple sugars.
Because simple sugars feed cancer, I advise you to avoid carbohydrates and
sugars in your dog’s diet.
Complex carbohydrates, on the other hand, can be a good source of energy
for your dog’s body while she fights cancer. Oatmeal and brown rice are both
good sources of energy. There is even some evidence that the polysaccharides
in their bran are cancer-fighters! As you’ll see later on, I include both of these
grains in the Dog Cancer Diet."

We were a bit overwhelmed with Dr. D's fresh diet b/c he said frozen veggies were fine to use but then he called for cottage cheese, turkey necks, etc.  I was afraid that some of the fresh ingredients would be hard to keep.  I found another diet developed by Dr. Ogilvie of Colorado State, which was very similar to Dr. D's.  Dr. Ogilvie used the meat portion, but then substituted supplements (crushed and mixed with the meat) for the fresh veggies and cottage cheese/turkey necks, etc.  We did a combination - we used the meats, frozen veggies which were cooked then mushed, and then supplements for the other parts.  We would cook large batches (took about three hours) and then package it into freezer bags of 4-day portions.  This usually lasted us about three weeks (keeping in mind that his diet was also 1/2 kibble).  Each meal would then consist of 1 cup home-cooked, 1 cup kibble and some fresh oatmeal to bind it all together.

Happiest dog ever at mealtime.