In this case, the specific percentages are all the significance. When a lot of the factors are controllable and a lot of them are uncontrollable, the most reasonable question is "How much do the controllable factors actually change the odds?"
Short of quitting smoking, there's almost no way to do that, because you don't know what the factors are or how they're weighed & influenced by individual genetic, immune, and metabolic factors.
> "How much do the controllable factors actually change the odds?"
Not only does nobody know, nobody has the foggiest notion. I've never seen a relevant population-wide observational study that wasn't so full of methodological flaws that you could spend hours picking apart its defects.
Of course we know that there's a set of factors associated with the development of cancer -- like, e.g., long-term exposure to polonium in drinking water -- but there's also a large set of factors that nobody is aware of or which can never be controlled for. To use only the first set -- the set of what we know and can control for -- to accurately estimate the odds of contracting cancer within the next five years is impossible.