Chronic obstructive pulmonary disease as a systemic risk factor for cancer - a nationwide cohort study in Korea

Sep 22, 2026

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Chronic obstructive pulmonary disease (COPD) is increasingly recognized as a systemic condition with extrapulmonary comorbidities, yet evidence for cancers beyond lung cancer remains limited after accounting for lifestyle, demographic, and socioeconomic factors. This nationwide Korean cohort study used the Korean National Health Insurance Service–Health Screening Cohort (2002–2019), defining COPD and exacerbations via ICD-10 codes and treatment records.

LanguageEnglish

CategoryResearch & Report

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Pages12

Reading Time30 min

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Abstract

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Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease as a systemic risk factor for cancer: a nationwide cohort study in Korea Joo-Hee Kim,1 Ho Suk Kang,2 Dae Myoung Yoo,3 Kyeong Min Han,3 Nan Young Kim,4 Hyo Geun Choi,5 Mi Jung Kwon 6 To cite: Kim J-H, Kang HS, Yoo DM, et al. Chronic obstructive pulmonary disease as a systemic risk factor for cancer: a nationwide cohort study in Korea. BMJ Open Respir Res 2026;13:e003939 . doi:10.1136/ bmjresp-2025-003939 ► Additional supplemental material is published online only. To view, please visit the journal online ([https://doi](https://doi). org/10.1136/bmjresp-2025- 003939) . J-HK and HSK contributed equally. Received 18 November 2025 Accepted 30 April 2026 © Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group. For numbered affiliations see end of article. Correspondence to Dr Mi Jung Kwon; [mulank@hanmail.net](mulank@hanmail.net) ABSTRACT Background Chronic obstructive pulmonary disease (COPD) is increasingly recognised as a systemic condition with extrapulmonary comorbidities including malignancy. While the association between COPD and lung cancer is well established, evidence for extrapulmonary cancers, particularly after accounting for lifestyle, demographic and socioeconomic factors, remains limited. Methods We conducted a nationwide population-based cohort study using the Korean National Health Insurance Service–Health Screening Cohort (2002–2019). After exclusions and propensity score overlap weighting, 532 174 patients with COPD and 1891601 matched controls were included. COPD and exacerbations were defined using International Classification of Diseases, 10th Revision codes and treatment records. Cox proportional hazards models and E-value analyses were used to estimate associations and assess the potential impact ofunmeasured confounding. Results During up to 16 years of follow-up, COPD was associated with a 52% higher overall cancer risk (HR 1.52, 95% CI 1.50 to 1 .53), independent of demographic, lifestyle and clinical factors. Increased risks were observed for 11 of 14 site-specific cancers, with the strongest associations for lung (HR 3.68), bladder (HR 1.58), haematological (HR 1 .45) and kidney cancers (HR 1 .43) . COPD exacerbations were also associated with increased overall cancer risk (HR 1 .48, 95% CI 1.46 to 1.50), with broadly similar patterns across site-specific cancers. Associations were consistent across sex, age and smoking strata and were unlikely to be explained by unmeasured confounding based on E-value analyses. Conclusions COPD and exacerbations were associated with increased risks of overall and multiple site-specific cancers beyond the lungs. These findings support the systemic nature of COPD. INTRODUCTION Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition characterised by persistent airflow limitation and chronic inflammation, encompassing emphysema, central airway inflammation with mucociliary dysfunction, and structural changes in the small airways, including bronchiolitis.1 It poses a major global health WHAT IS ALREADY KNOWN ON THIS TOPIC | ⇒ Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of lung cancer, even after adjustment for smoking. However, evidence linking COPD to extrapulmonary cancers remains inconsistent, particularly in Asian populationsand in studies with detailed adjustment for lifestyle and socioeconomic factors.
WHAT THIS STUDY ADDS | | --- | | ⇒ In this nationwide Korean cohort, COPD was associated with increased risks of overall cancer and 11 of 14 site-specific cancers, including bladder, kidney, haematological, gastric and hepatobiliary cancers, in addition to lung cancer. These associations were observed across age, sex and smoking strata, and COPD exacerbations were also associated with increased ca

FAQs

What gap does this study address about COPD and cancer?

While COPD-lung cancer links are well established, the study targets uncertainty about extrapulmonary cancers, especially after adjusting for lifestyle, demographic, and socioeconomic factors.

How were COPD and exacerbations defined in the cohort?

COPD and exacerbations were defined using International Classification of Diseases, 10th Revision codes and treatment records in the Korean National Health Insurance Service–Health Screening Cohort (2002–2019).

What did the study find about overall and site-specific cancer risks?

Over up to 16 years, COPD was associated with a 52% higher overall cancer risk, and increased risks were seen for 11 of 14 site-specific cancers, with the strongest associations for lung, bladder, hematological, and kidney cancers.

Sep 22, 2026

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