Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy.
Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy; Department of Molecular and Translational Medicine, Università degli Studi di Brescia, Brescia, Italy.
Eur J Cancer. 2018 Nov;104:117-126. doi: 10.1016/j.ejca.2018.09.007. Epub 2018 Oct 19.
Cigarette smoking is an established risk factor for pancreatic cancer but an updated quantification of the association is lacking. Our aim is to provide the most accurate and updated estimate of the dose-response relationships between cigarette smoking and pancreatic cancer risk.
Using an innovative approach for the identification of original publications, we conducted a systematic review and meta-analysis of epidemiological studies published on the issue up to April 2017. Random effects models were used to provide pooled estimates for the cigarette smoking status; dose-risk relationships were evaluated using one-stage random effects models with restricted cubic splines.
Seventy-eight studies were included, providing a pooled relative risk (RR) of pancreatic cancer of 1.8 (95% confidence interval, CI: 1.7-1.9) for the current and 1.2 (95% CI: 1.1-1.2) for the former vs. never smokers. A sharp increase in pancreatic cancer risk was found already with a low number of cigarettes and up to 30 cigarettes/day (RR 2.2, 95% CI: 1.9-2.4). Similarly, the risk of pancreatic cancer steady increased after a few years of smoking up to 30 years (RR 1.8, 95% CI: 1.6-2.0). The risk rapidly decreased with increasing time since quitting and was 0.6 (95% CI: 0.5-0.7, for the former vs. current smokers) after 20 years of quitting.
The present meta-analysis indicates that pancreatic cancer risk sharply increases with a low number of cigarettes or after a few years of smoking and that it rapidly decreases a few years after cessation, although it takes almost 20 years to reach that of never smokers.
吸烟是胰腺癌的既定危险因素，但缺乏对这种关联的最新定量评估。我们的目的是提供吸烟与胰腺癌风险之间的剂量-反应关系的最准确和最新的估计。
使用一种创新的方法来确定原始出版物，我们对截至 2017 年 4 月发表的关于该问题的流行病学研究进行了系统评价和荟萃分析。使用随机效应模型提供吸烟状况的汇总估计值；使用具有限制立方样条的单阶段随机效应模型评估剂量-风险关系。
共纳入 78 项研究，提供了当前吸烟者患胰腺癌的相对风险 (RR) 为 1.8（95%置信区间，CI：1.7-1.9），前吸烟者为 1.2（95%CI：1.1-1.2）。对于从不吸烟者。已经发现，吸烟量低至 30 支/天（RR 2.2，95%CI：1.9-2.4）时，胰腺癌风险急剧增加。同样，吸烟几年后（RR 1.8，95%CI：1.6-2.0），胰腺癌风险也稳步增加。随着戒烟时间的增加，风险迅速下降，与当前吸烟者相比，戒烟 20 年后风险为 0.6（95%CI：0.5-0.7）。
本荟萃分析表明，胰腺癌风险随着吸烟量的减少或吸烟几年后急剧增加，并且在戒烟几年后迅速下降，但要达到从不吸烟者的水平需要近 20 年的时间。
