Most women had not been smoking long enough to do themselves in. But by the 1990s, those who have been smoking have been smoking throughout their entire adult lives. Also, people now are trying to quit, so effects of prolonged cessation are apparent. Essentially, what we can do now is assess the effects of very prolonged smoking. Smokers who started smoking before the age of 15 have twice the risk of lung cancer of those who started smoking after 20.
Fewer women quit smoking than men.
Among those still smoking in 1990, more women smoked heavily than in 1950, and more started smoking before age 20. For both men and women who continue to smoke, the risk of lung cancer increased substantially from 1950 to 1990. This appears to be due to the fact that smokers consume more cigarettes than they used to. Experts who commented on the study for WebMD say the findings give people who smoke a new reason to stop. It's never too late to decrease your cancer risk.