Patients who use steroid inhalers to control chronic obstructive pulmonary disease (COPD) could also be reducing their risk of lung cancer by as much as 30%, a study* published in the European Respiratory Journal shows.
The researchers evaluated 10 years' worth of medical and pharmacy data for between 1997–2007, for 39,676 adults in British Columbia in Canada who were diagnosed with COPD, including 994 people who were later diagnosed with lung cancer. They compared outcomes for people who took inhaled steroids versus those who used beta agonists.
There were 994 (2.5%) cases of lung cancer during follow-up, and use of steroids was associated with a 30% reduced risk of lung cancer (HR: 0.70 (95% CI: 0.61–0.80)).
"Results showed that if you had COPD and consistently used a steroid inhaler, your chances of getting lung cancer were between 25 per cent and 30 per cent lower compared to people who took other treatments," said Larry Lynd, a professor who leads the Collaboration for Outcomes Research and Evaluation project at UBC's faculty of pharmaceutical sciences and an associate member of the faculty of medicine.
COPD is a group of diseases, including emphysema and chronic bronchitis, that hamper airflow to the lungs and cause serious long-term disability and early death. Although there is no cure, treatments can help manage the disease.
"In Canada alone, more than 700,000 people have been ‘diagnosed’ with COPD," said study co-author Don Sin, professor of medicine at University of British Columbia and the Canada Research Chair in COPD.
"These results highlight the importance of identifying which of those patients may be at the highest risk for lung cancer and may benefit from therapy with inhaled steroids."
The study is limited by its reliance on administrative data, which limits the scope of data available for analysis, and the fact that COPD diagnosis was based solely on prescription records. For the next stage in this research, the researchers plan to do studies to understand how steroids reduce lung cancer risk in COPD patients.
"More work is clearly needed to understand the exact nature of the relationship between lung cancer risks and steroid use," said Lynd.
"Over the next few months, we will find out which COPD patients would benefit the most from inhaled steroids."
*A.J.N. Raymakers, M. Sadatsafavi, D.D. Sin, et al. Inhaled corticosteroids and the risk of lung cancer in chronic obstructive pulmonary disease (COPD): a population-based cohort study. European Respiratory Journal, 2019; DOI: 10.1183/13993003.01257-2018