Primary Thromboprophylaxis for the Prevention of Venous Thromboembolism in Cancer Patients with Central Venous Catheters: A Literature Review.

Cancer is a known risk factor for venous thromboembolism (VTE). The wider adoption of immunotherapy and anti-angiogenic drugs in recent years have increased this risk further. Central venous catheters (CVCs) are widely used access devices utilized to deliver infusion therapy, mostly in ambulatory settings. The endothelial injury associated with the use of these catheters adds to the risk of VTE to already high-risk patients. The introduction of direct oral anticoagulants (DOACs), with its proven efficacy and safety in multiple clinical indications, have renewed the attention to VTE prophylaxis in cancer patients with CVC. Several clinical trials and meta-analyses had shown that both apixaban and rivaroxaban are effective in lowering the risk of VTE, without increasing the risk of bleeding. Several risk assessment models (RAM) have utilized patient-related, tumor-related, and treatment-related factors, in addition to widely available biomarkers, like Hemoglobin (Hb) level, white blood cell (WBC) and platelets counts to stratify patients into two or three VTE risk levels. In this manuscript, we review the published clinical trials and meta-analyses that attempted to study the efficacy and safety of anticoagulants, mostly the DOACs, in cancer patients with CVCs. We will also propose a practical risk-directed approach to enhance VTE prophylaxis rate.