Purpose: Digoxin affects several cellular pathways involved in tumorigenesis. We sought to determine the association between digoxin use and pancreatic cancer risk and survival.
Methods: A nested case-control study using The Health Improvement Network (THIN), a population-representative database from the United Kingdom (UK). Cases included all individuals with incident diagnosis of pancreatic cancer. Each case was matched to up to four controls using incidence density sampling based on age, sex, practice site, calendar time, and duration of follow-up. Exposure of interest was digoxin therapy before cancer diagnosis. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between digoxin use and pancreatic cancer risk were estimated using conditional logistic regression. We further conducted a retrospective cohort study among pancreatic cancer cases using Cox regression model in order to evaluate the association between digoxin use and overall survival.
Results: We identified 4,113 cases with incident pancreatic cancer and 16,072 matched controls. The adjusted OR for diagnosis of pancreatic cancer among active digoxin users was 1.41 (95% CI 1.16-1.72). The risk did not change among active users with duration of therapy of more than 1 year (adjusted OR of 1.39, 95% CI 1.11-1.76). Digoxin was not associated with change in overall survival with an adjusted hazard ratio of 0.97 (95% CI 0.81-1.18).
Conclusions: Digoxin use was associated with modestly increased pancreatic cancer risk but did not affect overall survival.
Keywords: Cancer survival; Digoxin; Pancreatic cancer.