Breaking News:Lung Cancer Risk Rises with Prior Lung Disease– What Just Happened

LUNG cancer risk among people who have never smoked is gaining increasing attention, as this group now represents a growing proportion of global lung cancer cases. A new systematic review and meta-analysis suggests that a history of certain non-malignant lung diseases, particularly tuberculosis (TB) and chronic bronchitis, may be associated with a higher risk of lung cancer in never-smokers. 

Lung Cancer Risk Beyond Smoking History 

Smoking remains the dominant risk factor for lung cancer, but up to a quarter of cases worldwide now occur in individuals who do not smoke. Understanding additional contributors to lung cancer risk in this population is therefore a clinical priority. Previous lung diseases have been proposed as potential risk modifiers, but evidence has been inconsistent. 

To address this gap, researchers conducted a comprehensive meta-analysis of observational studies assessing the association between TB, asthma, and chronic bronchitis and lung cancer among adults who never smoked. 

What the Meta-Analysis Found 

The analysis included 20 case–control studies and five cohort studies, identified through searches of PubMed and Embase up to July 15, 2025. All studies focused on adults aged over 18 years with no smoking history. 

In pooled analyses of case–control studies, prior TB was associated with a significantly increased lung cancer risk, with an odds ratio (OR) of 1.76 (95% CI: 1.47–2.11). Chronic bronchitis was also linked to higher risk (OR: 1.36, 95% CI: 1.07–1.72). Both associations showed low heterogeneity, suggesting relative consistency across studies. 

Asthma was associated with a numerically increased risk (OR: 1.34), but this finding did not reach statistical significance and showed moderate heterogeneity, indicating more variable results. 

Among cohort studies, TB was again associated with higher lung cancer risk (hazard ratio: 1.64), although this estimate narrowly missed statistical significance and was marked by substantial heterogeneity. 

Interpreting Inflammatory Lung Disease Signals 

From a mechanistic perspective, chronic inflammation, fibrosis, and immune dysregulation following TB or chronic bronchitis may plausibly contribute to carcinogenesis. However, the authors caution that observational data cannot establish causality, and residual confounding cannot be excluded. 

For clinicians, the findings reinforce the importance of considering prior lung disease when assessing lung cancer risk in never-smokers, particularly in patients with a history of TB or chronic bronchitis. The authors highlight the need for future studies in more diverse populations and for analyses stratified by sex, ethnicity, and socioeconomic status to refine risk assessment and inform prevention strategies. 

Reference 

Swami N et al. Associations between prior lung diseases and risk of lung cancer in populations with no smoking history: a systematic review and meta-analysis. Chest. 2026; DOI:10.1016/j.chest.2025.12.034.