A new study published in the journal of Nature Scientific Reports showed that airway mucus plugs on chest computed tomography indicate an increased risk of lung cancer in people with chronic obstructive pulmonary disease (COPD). Lung cancer growth is closely linked to COPD, which is a major source of morbidity and death globally. Lung cancer and COPD have a complex relationship that includes common risk factors like smoking, long-term inflammation, and structural alterations in the airways. Mucus plugging is one of the pathological characteristics of COPD that has become a significant clinical and prognostic indicator. Increased mucus production and poor clearance result in increased hypoxia, recurring infections, and ongoing airway blockage. In addition to these consequences, mucus plugs provide a confined environment of persistent inflammation, oxidative stress, and chronic irritation, all of which may be factors in lung cancer development. According to recent data, those with COPD who have mucus plugs may be more susceptible to lung cancer than those who do not. Investigating this relationship is essential for enhancing risk assessment, directing monitoring tactics, and promoting early treatments for patients at high risk. The purpose of this study was to ascertain if mucus plugs are linked to a higher risk of lung cancer in individuals with COPD. A retrospective cohort analysis of COPD patients treated at a teaching hospital from 2004 to 2020 was carried out by researchers. The incidence of lung cancer was the main outcome, while the histologic subtypes of lung cancer were secondary outcomes. Of the 616 individuals with COPD, 360 (58.4%) did not have mucus plugs, whereas 256 (41.7%) did. Lung cancer occurred in 56 individuals with a median observation duration of 66 months. An elevated risk of lung cancer was substantially linked to mucus plugs (adjusted HR = 2.281 [95% CI = 1.192-4.363], P-value = 0.013).Interestingly, even in patients who did not fit the traditional screening criteria for lung cancer, this connection was substantial. Adenocarcinoma was not substantially more common in patients with mucus plugs, whereas squamous cell carcinoma was (P-value = 0.001).Overall, mucus plugs are linked to an increased risk of lung cancer, especially squamous cell carcinoma, in people with COPD. Mucus plug users had a more than twofold increased risk of lung cancer, with a notably higher risk for squamous cell carcinoma but not adenocarcinoma, when monitored for a median of 66 months.Source:Kim, S. J., Park, H., Lee, H. J., Lee, J.-K., Heo, E. Y., Jin, K. N., Kim, D. K., & Lee, H. W. (2025). Mucus plug and lung cancer incidence in patients with COPD. Scientific Reports, 15(1), 30193. https://doi.org/10.1038/s41598-025-13501-6