BACKGROUND Chronic inflammation has been implicated in the pathogenesis of several cancers, including lung and laryngeal cancer. The objective of the study is to elucidate the association between ICS use and diagnosis of lung and laryngeal cancer.

METHODS A nested case-control study based on the Korean national claims database included new adult users of inhaled medications between January 1, 2007, and December 31, 2010. Patients diagnosed with lung cancer or laryngeal cancer after enrollment were identified as cases and up to five control individuals matched for age, sex, diagnosis of asthma or COPD, Charlson Comorbidity Index scores, number of health care visits, and initiation date were selected.

RESULTS From the 792,687 eligible cohort, 9177 individuals diagnosed with lung cancer were matched with 37,048 controls. Additionally, 408 laryngeal cancer patients and 1651 controls were matched. ICS use was associated with a decreased rate of lung cancer diagnosis [adjusted odds ratio (aOR), 0.79; 95% confidence interval (CI), 0.69-0.90]. The inverse association between ICS use and lung cancer risk was dose dependent (P < 0.0001 for the trend). However, no reduction in the risk of laryngeal cancer among ICS users was identified (aOR, 1.06; 95% CI, 0.62-1.18).

CONCLUSION The use of ICS is associated with a reduced risk of lung cancer but not of laryngeal cancer.