Is digoxin use for cardiovascular disease associated with risk of prostate cancer?
Digoxin is a commonly used medication for heart failure and cardiac arrhythmias that has recently been suggested as a novel chemotherapeutic agent. Preclinical studies of prostate cancer (PCa) have shown anti-tumor activity with digoxin. We explore the relationship between use of digoxin and PCa risk. Data from a population-based case-control study of incident cases aged 35-74 years at PCa diagnosis in 2002-2005 in King County, Washington were available. Controls were identified by random digit dialing and frequency matched by age. Use of digoxin was determined from in-person questionnaires regarding medical and prescription history. The relationship of digoxin use with PCa risk was evaluated with logistic regression. One thousand one cases of PCa and 942 controls were analyzed. The prevalence of digoxin use in controls was 2.7%, and use was positively correlated with age. In multivariate analysis adjusting for age, race, PSA screening, and family history of PCa, digoxin use was associated with a reduction in the odds ratio of PCa (OR 0.58, 95% CI: 0.30-1.10). Among those with ≥3 PSA tests over the preceding 5 years (546 cases, 380 controls), digoxin use was associated with a stronger reduction of PCa risk (OR 0.44, 95% CI: 0.20-0.98).
These data indicate digoxin use may be associated with a reduction in risk of PCa. Given the potential mechanisms by which digoxin may exert an anti-neoplastic effect and other recent studies showing a negative association between digoxin use and PCa, further research is warranted.