Which will give you cancer faster cigarettes or snuff?

Neither is "guaranteed" to give you cancer. Even Tobacco Control concede that less than half of smokers die from a 'smoking related' condition, deaths from various types of cancer making up a small fraction of those claimed to be "smoking related".

Snuff is generally considered 'safer' than cigarettes (although Tobacco Control will say they are both as bad - despite the evidence completely exposing their opinion as pure Propaganda).

I personally would be more concerned over a family history of cancer than any other suspected contributory factor.