Cancer risk in long-term users of vitamin K antagonists: a population-based case-control study

Int J Cancer. 2013 Jun 1;132(11):2606-12. doi: 10.1002/ijc.27905. Epub 2012 Nov 2.


Some evidence suggests that long-term use of vitamin K antagonists (VKAs) has a cancer chemopreventive effect. Such an effect would have considerable implications in terms of understanding tumor biology. To evaluate if long-term VKA treatment influences the risk of developing cancer, we performed a matched case-control analysis. We used data from four Danish nationwide registers. Cases were all Danish individuals with a first-time cancer diagnosis (except nonmelanoma skin cancer) between 2000 and 2009. For each case, eight controls, matched by birth year and gender, were selected from the source population by risk-set sampling. Long-term VKA use was defined as exposure to VKA for a period of 3 or more years. Conditional logistic regression was used to compute odds ratios (ORs) for cancer associated with long-term VKA exposure, adjusting for potential confounders. Prespecified subanalyses were performed for selected cancer sites, subgroups and measures of exposure. A total of 238,196 cases and 1,713,176 controls were included. The adjusted OR for cancer associated with long-term VKA exposure was 0.99 (95% CI: 0.95-1.02). Long-term VKA use was associated with increased ORs for alcohol- or obesity-related cancer sites, whereas we observed a decreased risk of prostate cancer (OR: 0.86; 95% CI: 0.78-0.95). Our study does not support a general chemopreventive effect of VKA drugs. However, in accordance with findings from previous studies, we found an inverse association between use of VKA and prostate cancer.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Anticoagulants / adverse effects*
  • Case-Control Studies
  • Denmark / epidemiology
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / epidemiology
  • Neoplasms / etiology*
  • Neoplasms / metabolism
  • Prognosis
  • Risk Factors
  • Vitamin K / antagonists & inhibitors*


  • Anticoagulants
  • Vitamin K