I already assume vaping does cause cancer, because I'm conditioned to believe that...
Everything enjoyable is bad.
Therein lies the most deadly "cancer". The Great Cancer of Enjoyment, under which all lesser cancers fall.
And it's true...everything enjoyable, even apple pie, is bad. You see, people who enjoy restricting the enjoyments of others are a very large group, and from what I've seen, they are far more hedonistic than my mere smoke and vapor could ever provide. Due to that group's tireless pursuit of enjoyment, my opposing enjoyment will definitely, without a doubt, turn out to be cancerous. Hence, it's guaranteed that vaping is cancerous. Even if the risk is micro-miniscule, it will be found to be damaging, backed-up with concrete proof, and branded with an ominous sounding name, like "Diacetyl".
Though I don't partake, I do understand how it might be enjoyable to view groups other than yours as "at greater risk". Must be very satisfying, that illusionary feeling of invulnerability, when you can point at so many other groups and say "Thy're all gonna die from their excesses".
I wouldn't have stopped smoking if I didn't enjoy vaping more. If and when I contract cancer from either, at least I'll be able to rationalize it as collateral damage from having fun. A lot of people aren't so lucky...they live lives of pure...purity and still get cancer for no apparent reason whatsoever.