Primary Thromboprophylaxis in Patients With Malignancy and Central Venous Catheters

Inclusion Criteria:

* Patients 18 years of age or older with a new or existing diagnosis of cancer and a CVC inserted in the last 72 hours.

Exclusion criteria:

1. CVC in place for \>72 hours
2. Patient requires anticoagulation for other indications
3. Concomitant use of dual antiplatelet therapy
4. Major bleeding event in the last 4 weeks
5. Patients receiving concomitant systemic treatment with strong inhibitors of both CYP 3A4 and P-gp (such as cobicistat, ketoconazole, itraconazole, posaconazole, or ritonavir).
6. Known pregnancy or plan to become pregnant in next 3 months
7. Severe renal insufficiency (Creatinine clearance \<30 mL/min (defined by Cockcroft-Gault) in the previous 3 months
8. Documented severe liver disease (e.g., acute clinical hepatitis, chronic active hepatitis or cirrhosis) in the previous 3 months
9. Known thrombocytopenia (platelet count \< 50x 109/L) in the previous 3 months
10. Known allergy to rivaroxaban
11. Life expectancy \<3 months
12. History of condition at increased bleeding risk including, but not limited to:

    1. cerebral infarction (hemorrhagic or ischemic), active peptic ulcer disease with recent bleeding, spontaneous or acquired impairment of hemostasis in the past 4 weeks.
    2. Chronic hemorrhagic disorder
13. Primary malignancy diagnosis of basal cell or squamous cell carcinoma of the skin only
14. Refused or unable to obtain consent