OBJECTIVE: To examine the association between digoxin exposure and mortality in men with prostate cancer using linked Irish National Cancer Registry and pharmacy claims data.
PATIENTS AND METHODS: Prostate cancer cases were identified from the database and digoxin exposure at prostate cancer diagnosis was identified from prescription claims. Digoxin users were matched to non-users using a propensity score to identify men with similar cardiovascular comorbidity. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for the association between digoxin exposure and all-cause and prostate cancer-specific mortality (PCSM). Analyses were repeated in the propensity score-matched cohort. Effect modification of treatment with radiation or androgen-deprivation therapy by digoxin exposure was also assessed.
RESULTS: In all, 5732 men with a prostate cancer diagnosis (2001-2006) were identified (digoxin exposed, 391). The median follow-up was 4.3 years. Digoxin exposure was associated with a small non-significant increase in PCSM in the full cohort (HR 1.13, 95% CI 0.91, 1.42) and the propensity. score-matched cohort (HR 1.17, 95% CI 0.88, 1.57). Adjusted HRs for all-cause mortality were increased for digoxin exposed men (HR 1.24, 95% CI 1.07, 1.43). Interactions with treatments received were not significant.
CONCLUSIONS: These results suggest digoxin exposure is not associated with reduced PCSM. Further investigation of other cardiac glycosides that have shown anti-cancer potential may be warranted.
Written by:
Flahavan EM, Sharp L, Bennett K, Barron TI. Are you the author?
Department of Pharmacology and Therapeutics, Trinity College, University of Dublin, Dublin, Ireland.
Reference: BJU Int. 2013 Jun 13. Epub ahead of print.
doi: 10.1111/bju.12287
PubMed Abstract
PMID: 23937513
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