COPD is a major comorbidity in lung cancer screening (LCS) cohorts, with a high prevalence of undiagnosed COPD. Combining symptom assessment with spirometry in this setting may enable earlier diagnosis of clinically significant COPD and facilitate increased understanding of lung cancer risk in COPD. In this study, we wished to understand the prevalence, severity, clinical phenotype and lung cancer risk of individuals with symptomatic undiagnosed COPD in a LCS cohort.

16 010 current or former smokers aged 55–77 years attended a lung health check as part of the SUMMIT Study. A respiratory consultation and spirometry were performed alongside LCS eligibility assessment. Those with symptoms, no previous COPD diagnosis and airflow obstruction were labelled as undiagnosed COPD. Baseline low-dose computed tomography (LDCT) was performed in those at high risk of lung cancer (PLCO_m2012 score ≥1.3% and/or meeting USPSTF 2013 criteria).

Nearly one in five (19.7%) met criteria for undiagnosed COPD. Compared with those previously diagnosed, those undiagnosed were more likely to be male (59.1% versus 53.2%; p<0.001), currently smoking (54.9% versus 47.6%; p<0.001) and from an ethnic minority group (p<0.001). Undiagnosed COPD was associated with less forced expiratory volume in 1 s impairment (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2: 85.3% versus 68.4%; p<0.001) and lower symptom/exacerbation burden (GOLD A and B groups: 95.6% versus 77.9%; p<0.001) than those with known COPD. Multivariate analysis demonstrated that airflow obstruction was an independent risk factor for lung cancer risk on baseline LDCT (adjusted OR 2.74, 95% CI 1.73–4.34; p<0.001), with a high risk seen in those with undiagnosed COPD (adjusted OR 2.79, 95% CI 1.67–4.64; p<0.001).

Targeted case-finding within LCS detects high rates of undiagnosed symptomatic COPD in those most at risk. Individuals with undiagnosed COPD are at high risk for lung cancer.

COPD 是肺癌筛查 (LCS) 队列中的主要合并症，未确诊的 COPD 患病率很高。在这种情况下，将症状评估与肺活量测定相结合可能有助于早期诊断有临床意义的慢性阻塞性肺病，并有助于加深对慢性阻塞性肺病肺癌风险的了解。在这项研究中，我们希望了解 LCS 队列中有症状的未确诊 COPD 个体的患病率、严重程度、临床表型和肺癌风险。

作为 SUMMIT 研究的一部分，16 010 名年龄在 55-77 岁的当前或曾经吸烟者参加了肺部健康检查。在进行 LCS 资格评估的同时，还进行了呼吸咨询和肺活量测定。那些有症状、既往没有慢性阻塞性肺病诊断且气流阻塞的患者被标记为未诊断的慢性阻塞性肺病。对肺癌高风险人群（PLCO _m2012评分≥1.3% 和/或符合 USPSTF 2013 标准）进行基线低剂量计算机断层扫描 (LDCT)。

近五分之一 (19.7%) 符合未确诊慢性阻塞性肺病的标准。与先前诊断的患者相比，未诊断的患者更有可能是男性（59.1% vs 53.2%；p<0 id=25> vs 47.6%；p<0 id=26> vs 68.4%；p<0 id=27>与已知 COPD 患者相比，为 77.9%；p<0.001）。多变量分析表明，基线 LDCT 上气流阻塞是肺癌风险的独立危险因素（调整后 OR 2.74，95% CI 1.73-4.34；p<0.001），未确诊 COPD 的患者风险较高（调整后 OR 2.79， 95% CI 1.67–4.64；p<0.001）。

LCS 内的有针对性的病例发现发现，高危人群中未确诊症状性 COPD 的比例很高。患有未确诊的慢性阻塞性肺病的人患肺癌的风险很高。