Cardiac glycosides use and the risk of lung cancer: a nested case–control study
1 Centre for Clinical Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal H3T 1E2, Quebec, Canada
2 Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
3 Pulmonology unit, Lyon Sud hospital, Hospices Civils de Lyon, Pierre Bénite, France
4 The faculty of medicine Lyon-Sud Charles Mérieux, Lyon 1 University, Oullins, France
5 Department of Oncology, McGill University, Montreal, Quebec, Canada
BMC Cancer 2014, 14:573 doi:10.1186/1471-2407-14-573Published: 8 August 2014
Two studies have reported statistically significant associations between the use of cardiac glycosides (CGs) and an increased risk of lung cancer. However, these studies had a number of methodological limitations. Thus, the objective of this study was to assess this association in a large population-based cohort of patients.
We used the United Kingdom Clinical Practice Research Datalink (CPRD) to identify a cohort of patients, at least 40 years of age, newly-diagnosed with heart failure, or supra-ventricular arrhythmia. A nested case–control analysis was conducted where each incident case of lung cancer identified during follow-up was randomly matched with up to 10 controls. Exposure to CGs was assessed in terms of ever use, cumulative duration of use and cumulative dose. Rate ratios (RRs) with 95% confidence intervals (CIs) were estimated using conditional logistic regression after adjusting for potential confounders.
A total of 129,002 patients were included, and followed for a mean (SD) of 4.7 (3.8) years. During follow-up, 1237 patients were newly-diagnosed with lung cancer. Overall, ever use of CGs was not associated with an increased risk of lung cancer when compared to never use (RR = 1.09, 95% CI: 0.94-1.26). In addition, no dose–response relationship was observed in terms of cumulative duration of use and cumulative dose with all RRs around the null value across quartile categories.
The results of this large population-based study indicate that the use of CGs is not associated with an increased risk of lung cancer.