Female smokers face higher mortality risk from lung cancer and chronic obstructive pulmonary disease than they did two decades ago, according to a study in the New England Journal of Medicine, demonstrating risk on par with that of men. The shift is likely explained by women starting smoking at younger ages. However, a second study in the same journal emphasized that although lifelong smokers lose about a decade of life compared to those who never smoked, quitting can help give years of life back to patients. "You're never too old to quit," said Dr. Michael Thun.