Schlecht N F, Franco E L, Pintos J, Kowalski L P
Department of Oncology and Epidemiology, McGill University, Montreal, Canada.
Epidemiology. 1999 Jul;10(4):412-8. doi: 10.1097/00001648-199907000-00009.
Tobacco smoking has long been identified as the most important risk factor for upper aero-digestive tract cancers. To investigate the effect of different tobacco types and the benefit of smoking cessation, we analyzed data from a case-control study of 784 cases of mouth, pharynx, and larynx cancers and 1,578 non-cancer controls in three metropolitan hospital areas in Brazil. Subjects were interviewed as to their smoking and drinking habits, demographics, environmental exposures, occupational history, health characteristics, and diet. Controlling for total tobacco and alcohol consumption, risks for ex-smokers compared with current smokers decreased substantially with time since cessation of the habit. Compared with never smokers, ex-smokers of >20 years had a relative risk (RR) of 1.98 [95% confidence interval (CI) = 1.0-3.8] for all upper aerodigestive tract cancers. RRs for long-term (>20 years) ex-smokers tended to be lower for mouth (RR = 1.61) and pharynx (RR = 1.52) than for larynx (RR = 3.63) cancers. The benefit of quitting was strongest for commercial cigarettes (RR = 1.45, 95% CI = 0.7-3.0) for ex-smokers of >10 years, as compared with smoking of black tobacco (RR = 2.57, 95% CI = 1.4-4.6), cigars (RR = 2.59, 95% CI = 0.6-11.6), and pipe tobacco (RR = 3.40, 95% CI = 1.3-8.8).
长期以来，吸烟一直被认为是上呼吸消化道癌症最重要的风险因素。为了研究不同烟草类型的影响以及戒烟的益处，我们分析了巴西三个大城市医院地区一项病例对照研究的数据，该研究涉及784例口腔、咽和喉癌病例以及1578名非癌症对照者。研究对象接受了关于吸烟和饮酒习惯、人口统计学、环境暴露、职业史、健康特征和饮食的访谈。在控制总烟草和酒精消费量的情况下，与当前吸烟者相比，戒烟者的风险随着戒烟时间的推移大幅降低。与从不吸烟者相比，戒烟超过20年的人患所有上呼吸消化道癌症的相对风险（RR）为1.98 [95%置信区间（CI）= 1.0 - 3.8]。长期（>20年）戒烟者患口腔癌（RR = 1.61）和咽癌（RR = 1.52）的RR往往低于喉癌（RR = 3.63）。与吸食黑烟草（RR = 2.57，95% CI = 1.4 - 4.6）、雪茄（RR = 2.59，95% CI = 0.6 - 11.6）和烟斗烟草（RR = 3.40，95% CI = 1.3 - 8.8）相比，对于戒烟超过10年的人来说，戒掉商业香烟的益处最为明显（RR = 1.45，95% CI = 0.7 - 3.0）。
