Venous thromboembolism (VTE), which includes deep-vein thrombosis and pulmonary embolism, is an important cause of morbidity and mortality amongst patients with cancer.1 The American Society of Clinical Oncology (ASCO) first published a guideline regarding the prophylaxis and treatment of VTE in patients with cancer in 2007, which has undergone numerous updates1, such as including direct oral anticoagulants (DOACs) as the options, and were published in the Journal of Clinical Oncology.1
VTE can complicate surgery, hospitalizations and systemic chemotherapy, and can significantly increase the costs associated with cancer treatments and hospitalizations.2 Patients with cancer are six times more likely to develop VTE than non-cancer patients, and VTE is the second-leading cause of death in cancer patients, after cancer itself.2
Previous guideline recommendations by ASCO and the European Society of Medical Oncology (ESMO) for the treatment of cancer-associated thrombosis (CAT) generally recommended the use of low molecular weight heparin (LMWH) for long term anticoagulant therapy.3,4 In recent years, four DOACs, dabigatran, rivaroxaban, apixaban, and edoxaban, have been compared with warfarin for stroke prevention in randomized controlled trials.5 The 2015 ASCO guideline did not provide recommendations for DOACs in CAT treatment due to a lack of evidence.3
In the latest update, it is recommended that high-risk outpatients with cancer (Khorana score of 2 or higher prior to starting a new systemic chemotherapy regimen) may be offered thromboprophylaxis with apixaban, rivaroxaban, or LMWH, provided there are no significant risk factors for bleeding and no drug interactions.1 In cancer patients with established VTE, initial anticoagulant treatments to prevent recurrence, such as LMWH, rivaroxaban, unfractionated heparin, and fondaparinux, are recommended.1
Long-term anticoagulation with LMWH, edoxaban, or rivaroxaban, lasting for at least 6 months are preferred due to improved efficacy over vitamin K antagonists.1 The guidelines further stated that anticoagulation with LMWH, DOACs, or vitamin K antagonists beyond the initial 6 months should be offered only to select patients with active cancer, such as those with metastatic disease or those receiving chemotherapy.1 The guidelines reiterated that anticoagulation beyond 6 months should be periodically reassessed to ensure a continued favorable risk benefit profile.1
This updated guideline also reaffirms the recommendation that most hospitalized patients with cancer and an acute medical combination will require thromboprophylaxis throughout their hospital stay. However, further validation of inpatient risk assessment models will be needed to guide the inpatient prophylaxis.1 Patients undergoing major cancer surgery should also receive prophylaxis starting before surgery and continuing for at least 7 to 10 days. Extended prophylaxis with LMWH for up to 4 weeks post-operatively is recommended for high-risk patients undergoing major open or laparoscopic abdominal or pelvic surgery for cancer.1 In low-risk patients, the decision on thromboprophylaxis duration should be made on a case-by-case basis.1
Despite the well-known association between VTE and cancer, patients are not aware of the risk and warning signs of thrombotic events.1 Oncology professionals should also provide patient education about the signs and symptoms of VTE, particularly in the settings with increased risk, such as major surgery and hospitalization.1
1. Key NS, Khorana AA, Kuderer NM, et al. Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: ASCO Clinical Practice Guideline Update. JCO. August 2019:JCO.19.01461.
2. Donnellan E, Khorana AA. Cancer and Venous Thromboembolic Disease: A Review. Oncologist. 2017;22(2):199-207.
3. Lyman GH, Bohlke K, Khorana AA, et al. Venous thromboembolism prophylaxis and treatment in patients with cancer: american society of clinical oncology clinical practice guideline update 2014. J Clin Oncol. 2015;33(6):654-656.
4. Mandalà M, Falanga A, Roila F, ESMO Guidelines Working Group. Management of venous thromboembolism (VTE) in cancer patients: ESMO Clinical Practice Guidelines. Ann Oncol. 2011;22 Suppl 6:vi85-92.
5. Julia S, James U. Direct Oral Anticoagulants: A Quick Guide. Eur Cardiol. 2017;12(1):40-45.