That said dietary studies are extremely hard to conduct in a controlled manner and thus replicate.
A diet which is heavy on plant based foods might be cancer preventative since you need to consume calories; additional plant material itself might contain molecules that help you combat cancer or at least serve as a barrier to potential carcinogenic pathogens.
As far as cancer and meat consumption goes it seems that pork and beef are the biggest offenders it’s not clear yet if it’s simply because they contain more pathogens which can impact humans as they are mammals or because those meats tend to be consumed at larger amounts.
Poultry and fish don’t seem to have as much impact with the latter showing no increase in cancer at all by most studies iirc.
https://www.cancer.gov/about-cancer/causes-prevention/risk/d...
Fish cooked at high temperatures is also not good.
Which link various pathogens native to the species consumed to cancer in humans as apparently the compounds that arise from cooking or processing meat which also appear in poultry and fish do not increase cancer risk by as much (or at all) as mammalian meat especially beef and pork despite having the same or even higher concentration of these compounds.
I prefer to say that a lack of fruits and vegetables causes cancer rather than they prevent cancer. Logically equivalent, but it leads me to consider them normal and packaged food abnormal.
Anyone can define normal for him or herself, but this way motivates me to eat more of them, as does discovering through experience how much more delicious they can be.