School of Public Health, The Institute for Chemical Carcinogenesis, The State Key Lab of Respiratory Disease, Guangzhou Medical University, Guangdong, China.
PLoS One. 2012;7(9):e46144. doi: 10.1371/journal.pone.0046144. Epub 2012 Sep 28.
Lung cancer and chronic obstructive pulmonary disease (COPD) share a common risk factor in cigarette smoking and a large portion of patients with lung cancer suffer from COPD synchronously. We therefore hypothesized that COPD is an independent risk factor for lung cancer. Our aim was to investigate the intrinsic linkage of COPD (or emphysema, chronic bronchitis and asthma) and lung cancer.
The present hospital-based case-control study included 1,069 patients with newly diagnosed lung cancer and 1,132 age frequency matched cancer-free controls. The odds ratios (ORs) for the associations between each previous pulmonary disease and lung cancer were estimated with logistic regression models, adjusting for age, sex, family history of cancer, BMI and pack year smoking. In meta-analysis, the pooled effects of previous pulmonary diseases were analyzed with random effects models; and stratification analyses were conducted on smoking status and ethnicity.
In the case-control study, previous COPD was associated with the odds for increased risk of lung cancer (OR = 1.29, 95% confidence interval [CI] = 1.00∼1.68); so were emphysema (OR = 1.55, 95%CI = 1.03∼2.32) and chronic bronchitis (OR = 1.22, 95%CI = 0.99∼1.67); while asthma was associated with odds for decreased risk of lung cancer (OR = 0.29, 95%CI = 0.16∼0.53). These associations were more pronounced in smokers (P<.05 for all strata), but not in non-smokers. In meta-analysis, 35 studies (22,010 cases and 44,438 controls) were identified. COPD was significantly associated with the odds for increased risk of lung cancer (pooled OR = 2.76; 95% CI = 1.85-4.11), so were emphysema (OR = 3.02; 95% CI = 2.41-3.79) and chronic bronchitis (OR = 1.88; 95% CI = 1.49-2.36); and these associations were more pronounced in smokers than in non-smokers (P<.001 respectively). No significant association was observed for asthma.
Previous COPD could increase the risk of lung cancer, especially in smokers.
肺癌和慢性阻塞性肺疾病（COPD）有一个共同的风险因素，即吸烟，并且很大一部分肺癌患者同时患有 COPD。因此，我们假设 COPD 是肺癌的一个独立危险因素。我们的目的是研究 COPD（或肺气肿、慢性支气管炎和哮喘）与肺癌之间的内在联系。
本项基于医院的病例对照研究纳入了 1069 例新诊断为肺癌的患者和 1132 例年龄频数匹配的无癌症对照者。采用 logistic 回归模型估计每种既往肺部疾病与肺癌之间的比值比（OR），并调整年龄、性别、癌症家族史、BMI 和吸烟包年数。采用随机效应模型对荟萃分析中既往肺部疾病的汇总效应进行分析，并对吸烟状况和种族进行分层分析。
在病例对照研究中，既往 COPD 与肺癌风险增加相关（OR=1.29，95%置信区间[CI]：1.00∼1.68）；肺气肿（OR=1.55，95%CI：1.03∼2.32）和慢性支气管炎（OR=1.22，95%CI：0.99∼1.67）也与肺癌风险增加相关；而哮喘与肺癌风险降低相关（OR=0.29，95%CI：0.16∼0.53）。这些关联在吸烟者中更为明显（所有分层 P<.05），但在非吸烟者中不明显。荟萃分析中，确定了 35 项研究（22010 例病例和 44438 例对照）。COPD 与肺癌风险增加显著相关（汇总 OR=2.76；95%CI：1.85-4.11），肺气肿（OR=3.02；95%CI：2.41-3.79）和慢性支气管炎（OR=1.88；95%CI：1.49-2.36）也与肺癌风险增加显著相关；这些关联在吸烟者中比在非吸烟者中更为明显（分别 P<.001）。未观察到哮喘与肺癌之间有显著关联。
既往 COPD 可增加肺癌风险，尤其是在吸烟者中。
