Tackling anticoagulation failure in patients with cancer

  • Zakai N
  • UNNH 2020
  • 19 Nov 2020

  • curated by Pavankumar Kamat
  • Univadis Clinical Summaries
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

From UNNH 2020 (A MedscapeLive conference).


  • Hematologist Neil Zakai, MD, Associate Professor at the University of Vermont, Burlington, suggests that patients with cancer who develop venous thromboembolism (VTE) despite anticoagulation should be further managed with clinical judgment.

Why this matters

  • Very little is understood about anticoagulation failure, with a lack of large trials to guide management and only a few guiding principles.

Key points

  • According to Dr Zakai, the preliminary issue to check is any potential inciting incident, such as medical nonadherence, an infection, or an interruption of anticoagulation.
  • Once the underlying problem is addressed, patients may be able to continue with their original anticoagulant.
  • However, cancer progression remains the primary reason for anticoagulation failure.
  • In such cases, Dr Zakai reports stepping up anticoagulation, increasing prophylactic dosing to full treatment dosing, and switching patients on a direct oral anticoagulant to a low-molecular-weight heparin.
  • Typically, anticoagulation for thrombosis prophylaxis continues as long as the cancer is active, more so when the patients are receiving hormonal treatments.
  • Dr Zakai emphasizes that there is variation in both thrombosis and bleeding risk change for cancer patients over time, and treatment needs to be matched.
  • Apixaban or enoxaparin is favorable for prophylaxis, with careful monitoring for bleeding and drug interactions with cancer therapies.
  • A recent trial showed a 59% reduction in VTE risk in ambulatory patients with cancer with apixaban 2.5 mg twice daily over 6 months vs placebo and a 6% absolute reduction, but at the cost of a 2-fold increase in bleeding risk, with an absolute 1.7% increase.
  • Dr Zakai cautions that patients in trials are selected for higher VTE and lower bleeding risks, so outcomes are likely to differ in real-world populations.