Venous Thromboembolism Prophylaxis and Treatment in Cancer Patients Clinical Practice Guidelines (ASCO, 2019)

American Society of Clinical Oncology

This is a quick summary of the guidelines without analysis or commentary. For more information, go directly to the guidelines by clicking the link in the reference.

October 04, 2019

Recommendations for thromboprophylaxis duration in specific settings are as follows:

  • Major surgery for cancer: At least 7-10 days

  • Major open or laparoscopic abdominal or pelvic surgery for cancer with high-risk features (eg, restricted mobility, obesity, history of VTE, additional risk factors): Extended LMWH prophylaxis for up to 4 weeks postoperatively

  • Lower-risk surgical settings: Case-by-case basis

Best Method for Preventing VTE in Cancer Patients With Established VTE

Initial pharmacological thromboprophylaxis agents may include UFH, LMWH, rivaroxaban, or fondaparinux. For cancer patients with newly diagnosed VTE who do not have severe renal impairment (ie, CrCl <30 mL/min) and who are initially receiving parenteral anticoagulation, LMWH is preferred over UFH for the first 5-10 days of anticoagulation.

LMWH, edoxaban, or rivaroxaban for at least 6 months is preferred over vitamin K antagonists for long-term anticoagulation. While vitamin K antagonists are inferior, they may be used if LMWH or direct oral anticoagulants are not available. The risk of major bleeding is increased with direct oral anticoagulants, in particular with gastrointestinal and possibly genitourinary malignancies. Use of direct oral anticoagulants also warrants caution in other settings with a high risk for mucosal bleeding. Check drug-to-drug interactions before using direct oral anticoagulants.

Select patients with active cancer (eg, those receiving chemotherapy, those with metastatic disease) should be offered pharmacologic thromboprophylaxis with LMWH, direct oral anticoagulants, or vitamin K antagonists beyond the initial 6 months. This duration of anticoagulation must be assessed intermittently to ensure the risk-to-benefit profile remains favorable.

Patients with a VTE diagnosis more than 4 weeks ago and patients with temporary contraindications to anticoagulation (eg, surgery) should not be offered vena cava filters. This recommendation is based on expert opinion (without randomized trial data), the uncertainty of short-term benefit, and increasing evidence of long-term harm. Also owing to concerns for long-term harm, filter insertion should not be offered for primary prevention or prophylaxis of pulmonary embolism or deep vein thrombosis. Filtration may be offered if absolute contraindications to anticoagulant therapy exist in an acute care setting (VTE diagnosis within the past 4 weeks) if the thrombus burden was considered life threatening.

Vena cava filtration may be offered as adjunctive therapy to anticoagulation in the case of thrombus progression (recurrent VTE or extension of existing thrombus) in spite of optimal anticoagulation therapy.

Patients with primary or metastatic CNS malignancies and established VTE should be offered anticoagulation as described for other cancer patients; however, the specific choice of agents and the selection of patients most likely to benefit remain undetermined.

Treat incidental pulmonary embolism and deep vein thrombosis the same as symptomatic VTE would be treated, owing to the similar clinical outcomes compared with cancer patients with symptomatic events.

Incidentally diagnosed isolated subsegmental pulmonary embolism or splanchnic or visceral vein thrombi treatment should be offered on a case-by-case basis, taking into consideration the potential risks and benefits of anticoagulation.

Anticoagulant Use to Improve Survival in the Absence of Established VTE

Pharmacologic thromboprophylaxis is not recommended to improve survival in cancer patients without established VTE.

Risk Prediction and Awareness of VTE in Cancer Patients

Owing to the significant variation in risk of VTE among individual cancer patients and cancer settings, VTE risk assessment should be initiated early and continued periodically thereafter; this is particularly important at the initiation of systemic antineoplastic therapy or when a patient is hospitalized. Individual risk factors (including cancer site or biomarkers) are not reliable identifiers of cancer patients at high risk of developing VTE. In ambulatory settings in patients with solid tumors undergoing systemic therapy, VTE risk assessment can be done using a validated risk assessment tool (eg, Khorana score).

Patients should be educated about VTE, specifically regarding settings that increase risk. These include major surgery, hospitalization, and during systemic antineoplastic therapy.

For more information go to Venous Thromboembolism (VTE).

For more Clinical Practice Guidelines, go to Guidelines.


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