Non-Small Cell Lung Cancer Risk Increases With Chronic Inflammatory Lung Disease

Regardless of smoking status, chronic inflammatory lung disease may contribute to the risk for lung cancer, with potential sex differences in the response to inflammatory events, according to a study published in the Annals of Epidemiology.

Researchers analyzed data from the ongoing case-control Maryland Lung Cancer Study to assess the relationship between chronic inflammatory lung disease and non-small cell lung carcinoma (NSCLC). In addition, researchers investigated whether race or sex affected a potential association between chronic inflammatory lung disease and NSCLC.

There was a strong association between having chronic inflammatory lung disease and developing NSCLC (adjusted odds ratio [aOR], 1.87; 95% CI, 1.54-2.28). 

After adjusting for relevant covariates, there was also a significant association between chronic inflammatory lung disease and higher odds of developing NSCLC in never, former, and current smokers (aOR, 1.99 [95% CI, 1.19-3.34]; aOR, 1.68 [95% CI, 1.29-2.20]; and aOR, 2.40 [95% CI, 1.62-3.57]; respectively). However, no statistical significance between chronic inflammatory lung disease and smoking status was found in the overall model or when stratified by sex or race.

Interestingly, in women, the risk for lung cancer was 7% higher for each 5-year increment in chronic inflammatory lung disease duration (aOR, 1.07; 95% CI, 1.02-1.13), yet it was 6% lower in men (aOR, 0.94; 95% CI, 0.89-0.99). The overall adjusted regression model found the association between asthma and the risk for NSCLC to be statistically significant (aOR, 1.42; 95% CI, 1.07-1.88), with women diagnosed with asthma found to be at a higher risk for NSCLC than men (aOR, 2.08; 95% CI, 1.40-3.10).

Researchers came to the conclusion that the inflammatory process associated with a disease may be a potential contributing factor to the risk of developing NSCLC because there was a significantly higher risk for NSCLC in individuals who had never smoked with either asthma or chronic obstructive pulmonary disease compared with individuals without a history of these diagnoses.

In addition, the risk for NSCLC in women compared with men suggest a possible sex difference in inflammatory events associated with the disease mechanisms. Therefore, clinicians should consider screening individuals diagnosed with an inflammatory respiratory condition for NSCLC, with an increased vigilance in women, as these factors potentially contribute to an increased risk for NSCLC.

Reference

Gardner LD, Loffredo CA, Langenberg P, et al. Associations between history of chronic lung disease and non-small cell lung carcinomas (NSCLC) in Maryland: variations by sex and race [published online May 7, 2018]. Ann Epidemiol. doi:10.1016/j.annepidem.2018.04.012