The following is a summary of “Detection of COPD in the SUMMIT Study lung cancer screening cohort using symptoms and spirometry” published in the December 2022 issue of Respiratory by Tisi et al.

There is a high frequency of undiagnosed Chronic obstructive pulmonary disease (COPD) in lung cancer screening (LCS) cohorts, making COPD a substantial comorbidity in these populations. Early detection of clinically relevant COPD and a better understanding of the risk of lung cancer in COPD may be possible when symptom evaluation is combined with spirometry in this scenario. The purpose of this study was to characterize the characteristics of an LCS cohort of people with symptomatic undiagnosed COPD, including their prevalence, severity, clinical profile, and risk of lung cancer. About 16,010 smokers, both present and ex-, between the ages of 55 and 77 participated in the SUMMIT Study’s lung health examination. LCS eligibility was determined after a consultation for respiratory issues and a spirometry test. 

Those showing signs of COPD but lacking a formal diagnosis were classified as having “undiagnosed COPD” due to airflow obstruction. Those with a high risk of lung cancer (PLCOm2012 score ≥1.3% and/or satisfying USPSTF 2013 criteria) underwent a baseline LDCT. 1 in 5 adults (19.7%) had COPD symptoms but had never been diagnosed. Those who had never received a diagnosis were more likely to be male (59.1% vs. 53.2%; P<0.001), smokers (54.9% vs. 47.6%; P<0.001), and members of a racial or ethnic minority (P<0.001). A lower forced expiratory volume in 1 second (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2: 85.3% versus 68.4%; P<0.001) and symptom/exacerbation burden (GOLD A and B groups: 95.6% versus 77.9%; P<0.001) were associated with an undiagnosed case of COPD compared to a diagnosed case. 

An increased risk of lung cancer was observed in those with undiagnosed COPD (adjusted OR 2.79, 95% CI 1.67-4.64; P<0.001), and multivariate analysis confirmed that airflow obstruction was an independent risk factor for lung cancer risk on baseline LDCT. A high prevalence of symptomatic COPD in at-risk individuals is detected through targeted case-finding within LCS. People with COPD who haven’t been diagnosed are at an increased risk of developing lung cancer.