Table 4.

Relationship between cardiac glycosides and the incidence of cancer in recent clinical studies

Authors (year), reference	Number of patients taking cardiac glycosides	Medication	Type of cancer	Main findings
Haux et al. (2001) [72]	9271	Digitoxin	Any	Digitoxin use increased the risk of cancer (SIR 1.27, 95 % CI 1.18–1.37). Plasma digitoxin levels were negatively correlated with the risk of cancer
Ahern et al. (2008) [73]	2890	Digoxin	Breast cancer	Digoxin use was associated with the increased risk of breast cancer (OR 1.30, 95 % CI 1.14–1.48). The risk was positively correlated with the duration of digoxin exposure (OR for 7–18 years of digoxin use 1.39, 95 % CI 1.10–1.74)
Biggar et al. (2011) [74]	104,648	Digoxin	Breast cancer	Current digoxin use increased the risk of breast cancer (RR, 1.39; 95 % CI, 1.32–1.46). In digoxin users, the risk was higher for ER-positive breast cancers (RR, 1.35; 95 % CI, 1.26–1.45) than for ER-negative breast cancers (RR, 1.20; 95 % CI, 1.03–1.40)
Biggar et al. (2012) [75]	104,648	Digoxin	Corpus uteri cancer	Current digoxin use increased the risk of corpus uteri cancer (RR 1.48, 95 % CI 1.32–1.65). (RR 1.06, 95 % CI 0.92–1.22) (RR 1.00, 95 % CI 0.79–1.25)
Biggar et al. (2012) [75]	104,648	Digoxin	Ovary cancer	Current digoxin use increased the risk of ovary cancer (RR 1.06, 95 % CI 0.92–1.22)
Biggar et al. (2012) [75]	104,648	Digoxin	Cervix cancer	Current digoxin use increased the risk of cervix cancer (RR 1.00, 95 % CI 0.79–1.25)
Platz et al. (2011) [76]	936	Digoxin	Prostate cancer	Current digoxin use decreased the risk of prostate cancer (RR 0.76, 95 % CI 0.61–0.95)