Abstract
Background Inhaled corticosteroids (ICS) are suggested for potential chemoprevention of lung cancer. Several observational studies in patients with chronic obstructive pulmonary disease (COPD) reported inconsistent results, either significant reductions in lung cancer incidence with ICS use or no effect. We assessed this association, using an approach that avoided biases affecting some of the studies.
Methods A cohort of patients with COPD, new users of long-acting bronchodilators over 2000–2014, was formed using the Quebec healthcare databases, and followed until 2015 for a first diagnosis of lung cancer. A 1-year delay after cohort entry was used to avoid protopathic bias and a 1-year latency period was included after the initiation of ICS use. A time-dependent Cox regression model was used to estimate the hazard ratio (HR) of lung cancer associated with ICS exposure, adjusted for covariates.
Results The cohort involved 63 276 subjects, including 63% receiving ICS, with 3743 lung cancers occurring during a mean follow-up of 5 years. The adjusted HR of lung cancer associated with any ICS exposure was 1.01 (95% CI 0.94–1.08), relative to no ICS use. The HR with longer time (>4 years) since ICS initiation was 0.92 (95% CI 0.83–1.03), while with higher mean daily ICS dose (>1000 μg fluticasone equivalents) was 1.36 (95% CI 1.03–1.81).
Conclusions Inhaled corticosteroid use is not associated with a reduction in lung cancer incidence in patients with COPD. Observational studies reporting such reduction may have been affected by time-related biases and the inclusion of patients with asthma. The proposition of a randomised trial warrants some caution.
Abstract
Large cohort study finds no reduction in lung cancer incidence with inhaled corticosteroids in COPD. Other observational studies reporting significant reductions probably affected by time-related biases and confounding from the inclusion of asthma patients. http://bit.ly/34Qeetd
Footnotes
Conflict of interest: S. Suissa reports grants and personal fees for advisory board work and lectures from Boehringer Ingelheim and Novartis, personal fees for lectures from AstraZeneca, outside the submitted work.
Conflict of interest: S. Dell'Aniello has nothing to disclose.
Conflict of interest: A.V. Gonzalez has nothing to disclose.
Conflict of interest: P. Ernst has nothing to disclose.
Support statement: This research was funded in part by grants from the Canadian Institutes of Health Research (CIHR) and the Canadian Foundation for Innovation (CFI). S. Suissa is the recipient of the Distinguished James ΜcGill Professorship award.
- Received July 2, 2019.
- Accepted November 9, 2019.
- Copyright ©ERS 2020
INDIVIDUALS
Log in using your username and password
LIBRARY USERS
Log in through your institution
Purchase access
CONTACT US
If you have any questions about the ERS publications website, please contact journals@ersnet.org