A significant amount of the shredded brown innards of most modern cigarettes is a paper product called "reconstituted tobacco" or "homogenized sheet tobacco," which is made from a pulp of mashed tobacco stems and other parts of the tobacco leaf that would otherwise go to waste. Manufacturers spray and impregnate reconstituted tobacco paper with nicotine and other substances lost during the process, along with as many as 600 chemical additives. These include several that may come as a surprise, such as ammonia, which aids in the delivery of nicotine, and chocolate, which masks the bitter taste of tobacco. Finally, the 'recon' is sliced to resemble shredded leaf tobacco.
So basically good research should compare people smoking quality cuban (once a week) with pipe smoker (once a day) with this poor creature addicted to synthetical 'tobacco' on her 20/day. And of course, since urban people are exposed to contaminated air from cars, control group must be taken from rural areas. I predict result that tobacco is not responsible for lung cancer, in absence of other air contamination factors.
You know, more than 90% of people with lung cancer ate cucumbers. So think twice before blaming tobacco.