We obsered inerse trends with pack-years smoked at eery age at onset except the ery elderly (>75 years of age), and the reduction of risk lessened with years since quitting smoking.

• 我们发现除非年纪很大（>75岁）才开始吸烟，否则任何时候开始吸烟并有数年烟龄的人都会出现这种负相关趋势，而戒烟后这种风险下降作用会减弱。