Just like with humans, nothing can prevent cancer. You can do all the right things and even improve the odds slightly and it will still happen either as a function of genes and heredity, aging, and the environment. Aging related illness is no more avoidable than aging itself. Good nutrition can help, regular vet exams and blood panels to catch things early, and weighing your cat regularly at home o a baby scale can reveal subtle weight loss, often a symptom of something going wrong. But eventually, as with all creatures, something will happen.
By that, I mean you fed your friend with wet/raw food (low/high end), supplements,
stayed indoors, etc...
Why did cancer still happen despite all of that?
Thanks.