Lubin Jay H, Alavanja Michael C R, Caporaso Neil, Brown Linda M, Brownson Ross C, Field R William, Garcia-Closas Montserrat, Hartge Patricia, Hauptmann Michael, Hayes Richard B, Kleinerman Ruth, Kogevinas Manolis, Krewski Daniel, Langholz Bryan, Létourneau Ernest G, Lynch Charles F, Malats Núria, Sandler Dale P, Schaffrath-Rosario Angelika, Schoenberg Janet B, Silverman Debra T, Wang Zuoyuan, Wichmann H-Erich, Wilcox Homer B, Zielinski Jan M
Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.
Am J Epidemiol. 2007 Aug 15;166(4):479-89. doi: 10.1093/aje/kwm089. Epub 2007 Jun 4.
A recent analysis showed that the excess odds ratio (EOR) for lung cancer due to smoking can be modeled by a function which is linear in total pack-years and exponential in the logarithm of smoking intensity and its square. Below 15-20 cigarettes per day, the EOR/pack-year increased with intensity (direct exposure rate or enhanced potency effect), suggesting greater risk for a total exposure delivered at higher intensity (for a shorter duration) than for an equivalent exposure delivered at lower intensity. Above 20 cigarettes per day, the EOR/pack-year decreased with increasing intensity (inverse exposure rate or reduced potency effect), suggesting greater risk for a total exposure delivered at lower intensity (for a longer duration) than for an equivalent exposure delivered at higher intensity. The authors applied this model to data from 10 case-control studies of cancer, including cancers of the lung, bladder, oral cavity, pancreas, and esophagus. At lower intensities, there was enhanced potency for several cancer sites, but narrow ranges for pack-years increased uncertainty, precluding definitive conclusions. At higher intensities, there was a consistent reduced potency effect across studies. The intensity effects were statistically homogeneous, indicating that after accounting for risk from total pack-years, intensity patterns were comparable across the diverse cancer sites.
最近的一项分析表明，吸烟导致肺癌的超额比值比（EOR）可以用一个函数来建模，该函数在总吸烟包年数上呈线性，在吸烟强度及其平方的对数上呈指数关系。每天低于15 - 20支香烟时，每包年的EOR随强度增加（直接暴露率或增强效力效应），这表明与较低强度（较长时间）的同等暴露相比，较高强度（较短时间）的总暴露风险更大。每天超过20支香烟时，每包年的EOR随强度增加而降低（反向暴露率或降低效力效应），这表明与较高强度的同等暴露相比，较低强度（较长时间）的总暴露风险更大。作者将该模型应用于10项癌症病例对照研究的数据，这些癌症包括肺癌、膀胱癌、口腔癌、胰腺癌和食管癌。在较低强度下，几个癌症部位的效力增强，但吸烟包年数的范围较窄增加了不确定性，无法得出明确结论。在较高强度下，各研究中效力效应一致降低。强度效应在统计学上是同质的，这表明在考虑总吸烟包年数的风险后，不同癌症部位的强度模式具有可比性。
