Sustained use of inhaled corticosteroids (ICS) is associated with a reduced risk for lung cancer in patients with chronic obstructive pulmonary disease (COPD), according to a study published in European Respiratory Journal.
In this retrospective cohort study, investigators accessed a set of population-based linked administrative data between 1997 and 2007 to identify a cohort of patients aged ≥50 years with COPD (N=39,676) based on prescription profiles linked to a registry of cancer patients. Patients had filled ≥3 prescriptions for an inhaled anticholinergic medication or short-acting beta-agonist. The date that the first prescription was filled was considered to be the patient’s index date, or COPD diagnosis date, for the purpose of this study. Preceding the index date, each patient was required to have a 1-year “wash-in” period in which no inhaled anticholinergic or short-acting beta-agonist prescription was filled. Use of ICS was given sufficient time (1 year) to affect the pathogenesis of lung cancer, and days of supply of each prescribed ICS medication were aggregated for any point in the study follow-up period. Potential confounders were incorporated into a multivariate model.
There were 994 diagnoses of lung cancer within the cohort during the follow-up period, and 372,075 dispensed prescriptions of ICS. The ICS that was most frequently prescribed was fluticasone propionate, with a median daily dose of 0.64 mg. A median of 60 days’ supply of ICS were prescribed per individual. Using a Cox regression model and adjusting for potential confounding variables, investigators determined that ICS exposure was associated with a 30% reduced risk of developing lung cancer (hazard ratio [HR], 0.70; 95% CI, 0.61-0.80). In a sensitivity analysis using a competing risk model to address concerns of death being a competing risk for lung cancer, the results were consistent with those of the primary analysis.
This study is limited by its design and reliance on administrative data that limit the scope of data available for analysis. Classification of COPD was based solely upon prescription profiles.
The researchers concluded that sustained use of ICS may be associated with reduced risk for lung cancer. These results underscore the importance of identifying patients who may be at the highest risk for lung cancer and may benefit from therapy with ICS.
Raymakers AJN, Sadatsafavi M, Sin DD, FitzGerald JM, Marra CA, Lynd LD. Inhaled corticosteroids and the risk of lung cancer in chronic obstructive pulmonary disease (COPD): a population-based cohort study [published online April 7, 2019]. Eur Respir J. doi:10.1183/13993003.01257-2018