One's predilection to cancer, mouth, lung, lymphatic and so forth is dependent on many things. Genetics and environment probably being the "big" ones. Your chances of getting mouth cancer are probably different than mine. (I've had one relative I know of who finally died from mouth cancer, it spread. He lived for years eating pap because he survived that long with most of his jaw being removed.) There are many thousands more cigarette smokers than pipe. Ergo, cigarette smoking has received the bulk of the research. And, mouth cancer is only one of the tragic deceases a pipe smoker opens himself to. Heart decease, blood pressure issues and so forth are others,
Just accept the fact that the pipe is a health hazard, fill a bowel, put flame to the blend and enjoy. Forget about trying to justify your choice, get comfortable with it by accepting the risks and enjoying the reward. I don't understand how anyone can enjoy a smoke when they are always trying to justify their poor choice. You're burning money, igniting tobacco, which unleashes the carcinogens, reducing oxygen to your brain, etc. and obviously not enjoying yourself if you are constantly trying to justify your choice. Actions have consequences. You'll find out in time if you've beaten the odds. So, enjoy the smoke as you quietly watch your moneys waft towards the sky/ceiling. Many of us do that.
I smoke cigars and the pipe. I also chew when smoking is prohibited. My brand of cigarettes is no longer available so I no longer smoke them after a titfy year two plus pack a day habit.. I've beaten the odds, according, to statistics with only two bypasses and a pacemaker implanted. I still feel the rewards out weigh the risks.