A 60 year old male with a past medical history of colon adenocarcinoma presents for left leg swelling after a road trip. He denies fever, chest pain, or shortness of breath. Vital signs are within normal limits. On exam, the left lower extremity is neurovascularly intact with a palpable distal pulse. There is swelling and pitting edema of the left thigh and calf compared to the right. Compartments are soft and there is full range of motion without difficulty. Which of the following is the recommended treatment of his suspected condition?
A: Low molecular weight heparin (LWMH)
B: Rivaroxaban
C: Unfractionated heparin (UFH)
D: Warfarin
Answer: Low molecular weight heparin
This patient is likely experiencing a deep vein thrombosis of his lower extremity given his multiple risk factors and exam findings. Therapeutic anticoagulation should be initiated in the emergency department as the patient follows up outpatient. According to the American Society of Clinical Oncology guidelines, the recommended treatment of venous thromboembolism (VTE) in patients with cancer is LMWH.
Rivaroxaban is a reasonable alternative but is associated with an increased risk of bleeding compared to LMWH. Subcutaneous UFH is not recommended for the outpatient treatment of acute VTE due to unpredictable bioavailability and effect requiring frequent monitoring. Warfarin causes an initial pro-thrombotic phase due to inhibition of protein C that would be potentially harmful in the case of active VTE which is why warfarin is typically co-administered with a secondary anticoagulant until the INR is in the desired therapeutic range for 2 consecutive days.
References:
Key NS, Khorana AA, Kuderer NM, et al. Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: ASCO Clinical Practice Guideline Update. J Clin Oncol. 2020;38(5):496-520. doi:10.1200/JCO.19.01461
Kline JA. Venous Thromboembolism Including Pulmonary Embolism. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020.
Slattery DE, Pollack, Jr CV. Thrombotics and Antithrombotics. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020.
Treatment of Venous Thromboembolism in Patients with Cancer: Subgroup Analysis of the Matisse Clinical Trials, www.researchgate.net/publication/24261105_Treatment_of_venous_thromboembolism_in_patients_with_cancer_Subgroup_analysis_of_the_Matisse_clinical_trials. Accessed 19 Apr. 2024.
