New Option for VTE Cancer Prophylaxis -- DOACs

Pam Harrison

August 12, 2019

In the updated clinical guidelines for the prevention and treatment of venous thromboembolism (VTE) in cancer patients, released by the American Society of Clinical Oncology (ASCO), the most notable change is the singling out of the direct oral anticoagulants (DOACs) as a new therapy option.

These include apixaban (Eliquis, Bristol-Myers Squibb), edoxaban (Lixiana, Daiichi Sankyo), and rivaroxaban (Xarelto, Bayer) for both the prevention and treatment of VTE in cancer patients.

The updated guidelines were published online on August 5 in the Journal of Clinical Oncology.

An expert panel, under lead author Nigel Key, MB, ChB, University of North Carolina at Chapel Hill, notes that the guidelines continue to recommend VTE prophylaxis for most hospitalized patients with cancer when accompanied by an acute medical illness.

Consideration may also be given to VTE prophylaxis for hospitalized patients who have an active malignancy but no additional risk factors, panel members add.

In contrast, thromboprophylaxis should not be given to patients who have been admitted to hospital for the sole purpose of undergoing a minor procedure or chemotherapy or to most ambulatory patients who receive cancer care as outpatients.

Nor should VTE prophylaxis be used for patients undergoing stem-cell bone marrow transplant, panel members add.

High-Risk Outpatients

On the other hand, high-risk outpatients who are about to start systemic chemotherapy may be considered for thromboprophylaxis with one of the DOAs, including apixaban, rivaroxaban, or low-molecular-weight heparin (LMWH), provided these patients are not at risk for bleeding or drug interactions.

Thromboprophylaxis may be more important for patients undergoing certain treatments for specific types of cancers. For example, multiple myeloma patients receiving either a thalidomide (Thalomnid, Celgene) or lenalidomide-based regimen or dexamethasone (multiple brands) or both should be offered thromboprophylaxis, they add. This should be achieved with either aspirin or LMWH if these patients are at low risk for VTE. LMWH should be given for those patients who are at higher risk.

"All patients with malignant disease undergoing major surgical intervention should be offered pharmacologic thromboprophylaxis with either unfractionated heparin (UFH) or LMWH unless there are bleeding contraindications," panel members continue. In this setting, the prophylactic regimen should be initiated preoperatively and should be continued for at least 7 to 10 days following surgery, they add.

For patients at high risk for VTE, including those with restricted mobility or obesity, LMWH should be extended for up to 4 weeks following major open or laparoscopic abdominal or pelvic surgery.

Mechanical methods may be used to supplement pharmacologic measures, panel members suggest, but they should not be used alone for the prevention of VTE unless pharmacologic interventions are contraindicated.

VTE Recurrence

To prevent recurrence of VTE in patients with established VTE, panel members recommend the use of LMWH, UFH, fondaparinux (Arixtra, Glaxo-Smith Klein), or rivaroxaban. They note that LMWH is preferred over UFH for patients who require parenteral anticoagulation.

"For long-term anticoagulation, LMWH, edoxaban or rivaroxaban for at least 6 months are preferred because of improved efficacy over vitamin K antagonists (VKAs)," panel members note.

Beyond 6 months, anticoagulation using LMWH, DOACs, or VKAs should be offered, but only to select patients, such as those with metastatic disease.

A vena cava filter should not be used in patients with established or chronic thrombosis, panel members advise. Nor should a filter be used in patients with temporary contraindications to anticoagulant therapy, such as those who require surgery.

On the other hand, a vena cava filter may be offered as an adjunct to anticoagulation for patients with recurrent VTE or for those in whom there is an extension of an existing thrombus, ASCO members write.

Panel members also felt that the use of anticoagulation should be considered for patients with primary or metastatic central nervous system malignancies and established VTE as described for other patients with cancer.

They also recommend that incidental pulmonary embolism and deep vein thrombosis be treated in the same way as symptomatic VTE, given that outcomes for patients with these conditions are similar.

At the same time, in the absence of VTE, the use of anticoagulants is not recommended to improve survival in patients with cancer.

"Patients with cancer should be assessed for VTE risk initially and then periodically thereafter, particularly when starting systemic antineoplastic therapy or at the time of hospitalization," panel members advise.

Patients need to be educated about the risks of VTE, especially when scheduled for major surgery, during hospitalization, and while receiving systemic antineoplastic therapy, they add.

Patients with cancer are increasingly required to pay a larger proportion of their treatment costs through deductibles and coinsurance arrangements with insurance companies.

"Discussion of cost can be an important part of shared decision making," panel members write.

"And clinicians should discuss with patients the use of less expensive alternatives when it is practical and feasible for treatment of the patient's disease," they add.

The authors' relevant financial relationships are listed in the original article.

J Clin Oncol. Published online August 5, 2019. Full text

Follow Medscape on Facebook, Twitter, Instagram, and YouTube


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.