Department of Epidemiology and Biostatistics, School of Public Health and Health Services, George Washington University, Washington, DC 20037, USA.
Chest. 2010 Sep;138(3):491-9. doi: 10.1378/chest.09-1909. Epub 2010 Feb 12.
Cigarette smoking is causally related to several cancers, particularly lung cancer, yet for some cancers there are inconsistent associations. This study investigates the association of smoking with other cancers by correlating them with the regional incidence rates for lung cancer, which was used as a proxy for cigarette smoking. This ecologic approach relating cigarette smoking to cancer using a large database avoids the limitations and bias present in case-control and cohort studies.
Based on the assumption that regions with a high rate of lung cancer also have a high rate of cigarette smoking, our original hypothesis is that these high-intensity regions will also have high rates of other cancers if they are associated with cigarette smoking. Linear regression and correlation analysis of regional incidence rates for lung cancer, obtained from the Surveillance, Epidemiology, and End Results (SEER) Program, were plotted with incidence rates of other cancers to determine the association between lung cancer and the other cancers.
Cancers that have a strong correlation with cigarette smoking in the literature also demonstrate a strong correlation with lung cancer. These cancers included urinary bladder, laryngeal, esophageal, colorectal, and kidney cancer. A number of cancers showed a weak association with cigarette smoking, such as pancreatic and liver cancer. Other cancers showed no correlation, such as ovarian and prostate cancer.
Cancers that respectively showed a strong or absent correlation with lung cancer in the SEER Program were similarly strongly or weakly correlated with cigarette smoking in the literature. Cancers with borderline correlations show ambiguous results or confounding variables in the literature.
吸烟与多种癌症，尤其是肺癌，有因果关系，但有些癌症的关联并不一致。本研究通过将吸烟与肺癌的区域发病率相关联，来调查吸烟与其他癌症的关联，而肺癌被用作吸烟的代表。这种利用大型数据库将吸烟与癌症相关联的生态方法避免了病例对照和队列研究中存在的局限性和偏倚。
基于这样一种假设，即肺癌发病率高的地区也有高吸烟率，如果这些地区与吸烟有关，那么它们也可能有高的其他癌症发病率。我们利用从监测、流行病学和最终结果（SEER）计划获得的肺癌区域发病率的线性回归和相关分析，与其他癌症的发病率进行作图，以确定肺癌与其他癌症之间的关联。
文献中与吸烟有很强相关性的癌症与肺癌也有很强的相关性。这些癌症包括膀胱癌、喉癌、食管癌、结直肠癌和肾癌。一些癌症与吸烟有弱相关性，如胰腺癌和肝癌。其他癌症则没有相关性，如卵巢癌和前列腺癌。
在 SEER 计划中与肺癌分别显示出强相关或无相关的癌症与文献中的吸烟也分别显示出强相关或弱相关。有边界相关性的癌症在文献中显示出不确定的结果或混杂因素。
