Smokers who kick the habit before age 45 can nearly eliminate their excess risk of dying from lung or other cancers, according to a study published in JAMA Oncology. Among more than 400,000 Americans followed for the study, smokers died of cancer—most often lung cancer—at three times the rate of non-smokers. However, smokers who managed to quit by age 45 lowered that excess risk by 87%. Among those who started smoking before age 18, cancer-related mortality was increased at least threefold, while the risk was increased four-fold for those who started before age 10. The study team estimated, however, that smokers who quit before age 35 eliminated their excess risk of cancer-related mortality, those who quit between ages 45 and 54 eliminated 78% of their risk, and those who quit between ages 55 and 64 cut their risk by 56%.