Rivaroxaban Versus Low-molecular-weight Heparin for Preventing Thrombosis in Cancer Patients

Inclusion Criteria:

* Age 18 to 85
* Histologically or cytologically confirmed advanced or metastatic solid tumors
* Patients will be received femoral venepuncture for apheresis by cell separator, which is the necessary process to perform following adoptive cell immunotherapy.
* Estimated life expectancy \> 3 months
* Adequate hematologic function, with WBC ≥ 3000/microliter, hemoglobin ≥ 9 g/dL (it is acceptable to have had prior transfusion), platelets ≥ 75,000/microliter; PT-INR \<1.5 (unless patient is receiving warfarin in which case PT-INR must be \<3), PTT \<1.5X ULN
* Adequate renal and hepatic function, with serum creatinine \< 1.5 mg/dL, bilirubin \< 1.5 mg/dL (except for Gilbert's syndrome which will allow bilirubin ≤ 2.0 mg/dL), ALT and AST ≤ 2.5 x upper limit of normal.

Exclusion Criteria:

* known conditions associated with high risk of bleeding, known history of hemorrhagic diathesis
* Platelet count \< 50 000 G/L
* Active bleeding
* Patients with a history of autoimmune disease, such as but not restricted to, inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis, scleroderma, or multiple sclerosis. Autoimmune related thyroid disease and vitiligo are permitted.
* Patients with obstructive jaundice
* Patients with Spleen hyperfunction
* Presence of an active acute or chronic infection including: a urinary tract infection, HIV (as determined by ELISA and confirmed by Western Blot). Patients with HIV are excluded based on immuno-suppression, which may render them unable to respond to the vaccine; patients with chronic hepatitis are excluded because of concern that hepatitis could be exacerbated by the injections.
* Pregnant or breast-feeding women，or lack of effective contraceptive treatment for women of childbearing age.;