Emphysema Treatment Gap and Gender Differences in a Lung Cancer Screening Cohort

Lung cancer screening (LCS) with low-dose computed tomography (LDCT) is a unique opportunity to improve diagnosis and treatment of chronic obstructive pulmonary disease (COPD) in high-risk individuals. Gender differences have been reported in the management of COPD, though inconsistently. We examined the factors associated with pharmacological treatment of COPD among LCS participants with radiologic visual emphysema and the gender-differences in treatment and symptoms of COPD.

Participants were recruited from the Quebec LCS program (smokers or ex-smokers aged 55-74 years with a PLCO_m2012 ≥2%) between April 2023 and July 2024. An LCS cohort was constituted from LCS participants with any level of visual emphysema on their LDCT scans and defined as having probable COPD. Primary outcome was pharmacological treatment for probable COPD defined as self-reported use of long-acting bronchodilators. Participants were screened for respiratory symptoms with the modified Medical Research Council (mMRC) and the COPD Assessment Test (CAT) scales. Probable symptomatic COPD was defined as visual emphysema on LDCT scan with mMRC score ≥1 and/or CAT score ≥10. Logistic regression was used to identify factors associated with the likelihood of pharmacological treatment for probable COPD, including gender, sociodemographic variables, radiologic emphysema severity, smoking, and body mass index. Gender-based differences in pharmacotherapy and symptoms were further examined using stratified analyses in males and females.

Among 1,026 participants undergoing LCS, 801 (78%) had visual emphysema of any level on LDCT, with 75% (603/801) of these lacking pharmacological treatment for probable COPD. Males were more likely to lack pharmacological treatment compared to females (58% vs. 42%). In multivariable analysis, the factors associated with treatment for probable COPD were female gender (OR 1.58; 95% CI: 1.11-2.24) and moderate-to-severe emphysema (OR 2.36; 95% CI: 1.64-3.41). Among participants screened for respiratory symptoms (397/603), 56% (221/397) were symptomatic (mean CAT score = 12.6 and mMRC score = 0.91). Females (111/174; 64%) reported more symptoms than males (110/223; 49%), particularly for minimal-to-mild emphysema: mean CAT = 10.3 and mMRC = 0.62 vs. mean CAT = 8.2 and mMRC = 0.41, respectively.

The lack of pharmacological treatment was frequent among LCS participants with symptomatic radiologic emphysema. The lack of treatment was associated with male gender and a lesser degree of radiologic emphysema. Females reported more symptoms for milder emphysema. Integrating respiratory diagnosis within LCS programs is an important opportunity to leverage the LDCT results and raise clinical suspicion of individuals with COPD. Raising awareness on the gender differences in pharmacological treatments is essential to close the treatment gap in COPD.