You cannot compare human incident of cancer to that of dogs, nor spaying/neutering to humans.
Dogs live 12-13 yrs. Humans live into their 80s and beyond if lucky.
Not comparing human incident of cancer to dogs.
and comparing hormone imbalances - humans can talk - dogs cannot.
and not 1 in 4 dogs get mammary cancer, it is an increase of 26% "chance"
When your dog is having hormonal imbalances and itchy skin and hair loss - this will not be connected to the spay from your vet...
Your dog will end up on a cycle of drugs for "possible" bacteria infection from scratching, steroids, diet changes, baths, topical's...as your dog gets older....well that's when cancers rear their head
Hormones play a huge part in development.
Also note that the Immune system has NOT fully developed, the dog will have gone through a series of vaccines - further lending an assault in the already fragile immune system, the denatured kibble diet, pesticide treatment to de-worm, prevent fleas and heartworm....then you put a 6 month old PUPPY (baby) under anesthetic drugs and take out their hormone producing gonads...
What's not to consider. One thing you can bet on, is your vet will always be there for you