There is a great homemade recipe often recommended by vets as a cancer fighter. But, dog's nutritional needs change as they grow and age. Pups need certain foods different from a year old. I'd discuss this with your vet of choice. Find a vet, reputable, with great references and run your wife's idea past him. I'd certainly refrain from such an idea until the pup matures. Also, one food doesn't fit all dogs. Watch the stools and look for any early signs of distress. Dogs take work but, the reward is well worth it.My wife seems to think she can prepare her own food for this dog. She has researched this. I’m worried though.
I had one dog with a mid-life cancer. My wife and I provided a vet recommended home cooked diet for four years. A pound of ground, lean beef, one pound broccoli, and a pound of cottage cheese. Meat and broccoli cooked, cooled and hand mixed with cottage cheese. Serving was a full cup in the morning and the same for the evening meal. We kept a serving in individual freezer containers, one always thawing on the counter. I stress, this was for a middle aged dog with cancer, following a successful removal of the cancer. We got four more quality years out of Brian Boru, a lovely Golden Retriever.