Warfarin sodium is an oral anticoagulant that has been shown in pre-clinical studies to inhibit the spread of cancer cells, which could potentially prolong survival in cancer patients.
However, to date, no population-based studies have been performed to test the association between warfarin use and cancer-specific mortality. Therefore, researchers from Ireland looked at data from the UK Clinical Practice Research Datalink and constructed four population-based cohorts of patients with breast, colorectal, lung and prostate cancer who were diagnosed between January 1998 and December 2010, and compared pre-diagnostic warfarin users to non-users.
Overall, 16,525 breast, 12,902 colorectal, 12,296 lung, and 12,772 prostate cancers were included in the study, and the use of warfarin before being diagnosed with cancer ranged between 2.4% to 4.7%.
The researchers found little evidence of an association between warfarin use and cancer-specific mortality in any of the cohorts (prostate: adjusted hazard ratio [HR] = 1.03, 95 % CI: 0.84–1.26; lung adjusted HR = 1.06, 95 % CI: 0.96–1.16; breast adjusted HR = 0.81, 95 % CI: 0.62–1.07 and colorectal adjusted HR = 0.88, 95 % CI: 0.77–1.01).
The study did not look at low molecular weight heparins, which may be well tolerated with fewer bleeding complications compared with warfarin, and have also shown potential to improve cancer survival.
The authors aimed to examine the association between warfarin use and cancer-specific mortality. There was little evidence of associations between pre-diagnostic use of warfarin and cancer-specific mortality in lung, prostate, breast, or colorectal cancer patients.