Background Inhaled corticosteroids (ICS) are suggested for potential chemoprevention of lung cancer. Several observational studies in patients with chronic obstructive pulmonary disease (COPD) reported inconsistent results, either significant reductions in lung cancer incidence with ICS use or no effect. We assessed this association, using an approach that avoided biases affecting some of the studies. Methods A cohort of patients with COPD, new users of long-acting bronchodilators over 2000–2014, was formed using the Quebec healthcare databases, and followed until 2015 for a first diagnosis of lung cancer. A 1-year delay after cohort entry was used to avoid protopathic bias and a 1-year latency period was included after the initiation of ICS use. A time-dependent Cox regression model was used to estimate the hazard ratio (HR) of lung cancer associated with ICS exposure, adjusted for covariates. Results The cohort involved 63 276 subjects, including 63% receiving ICS, with 3743 lung cancers occurring during a mean follow-up of 5 years. The adjusted HR of lung cancer associated with any ICS exposure was 1.01 (95% CI 0.94–1.08), relative to no ICS use. The HR with longer time (>4 years) since ICS initiation was 0.92 (95% CI 0.83–1.03), while with higher mean daily ICS dose (>1000 μg fluticasone equivalents) was 1.36 (95% CI 1.03–1.81). Conclusions Inhaled corticosteroid use is not associated with a reduction in lung cancer incidence in patients with COPD. Observational studies reporting such reduction may have been affected by time-related biases and the inclusion of patients with asthma. The proposition of a randomised trial warrants some caution. Large cohort study finds no reduction in lung cancer incidence with inhaled corticosteroids in COPD. Other observational studies reporting significant reductions probably affected by time-related biases and confounding from the inclusion of asthma patients. http://bit.ly/34Qeetd

中文翻译：

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吸入性皮质类固醇的使用和 COPD 患者肺癌的发病率

背景 建议吸入皮质类固醇 (ICS) 用于潜在的肺癌化学预防。几项针对慢性阻塞性肺病 (COPD) 患者的观察性研究报告了不一致的结果，要么使用 ICS 显着降低肺癌发病率，要么没有效果。我们使用一种避免影响某些研究的偏倚的方法评估了这种关联。方法 使用魁北克医疗保健数据库形成了一组 COPD 患者，即 2000 年至 2014 年间新使用长效支气管扩张剂的患者，并于 2015 年首次诊断为肺癌。队列进入后 1 年的延迟用于避免原发病偏倚，并在 ICS 使用开始后包括 1 年的潜伏期。使用时间依赖性 Cox 回归模型来估计与 ICS 暴露相关的肺癌的风险比 (HR)，并针对协变量进行调整。结果 该队列涉及 63276 名受试者，其中 63% 接受 ICS，平均 5 年随访期间发生 3743 例肺癌。与未使用 ICS 相比，与任何 ICS 暴露相关的肺癌调整后 HR 为 1.01（95% CI 0.94–1.08）。自 ICS 开始时间较长（>4 年）的 HR 为 0.92（95% CI 0.83–1.03），而更高的平均每日 ICS 剂量（>1000 μg 氟替卡松当量）为 1.36（95% CI 1.03–1.81）。结论 吸入性皮质类固醇的使用与 COPD 患者肺癌发病率的降低无关。报告这种减少的观察性研究可能受到时间相关偏倚和哮喘患者的影响。随机试验的提议值得谨慎。大型队列研究发现吸入皮质类固醇不会降低 COPD 患者的肺癌发病率。其他观察性研究报告的显着减少可能受时间相关偏差和纳入哮喘患者的混杂影响。http://bit.ly/34Qeetd