Risk assessment and primary prevention of VTE in patients with cancer: Advances, challenges, and evidence gaps

Venous thromboembolism (VTE) is a common complication in cancer patients, which is associated with increased morbidity and mortality as well as high risk of VTE recurrence and bleeding. Furthermore, it impairs quality of life, interferes with anti-cancer treatment schedules, and increases costs. Therefore, identifying patients at high VTE risk and primary prevention are of clinical importance. In ambulatory patients, specific risk assessment models and clinical trials on primary thromboprophylaxis with low-molecular-weight heparins and direct oral factor Xa inhibitors are available. In hospitalized medical patients, there is lack of evidence. In surgical patients, no specific VTE risk assessment tools have been developed. However, extended thromboprophylaxis after major abdominal and pelvic cancer surgery is recommended because VTE risk persists beyond hospital discharge. In this review, we provide an overview on thromboprophylaxis strategies for patients with cancer in the ambulatory, hospitalized, and surgical setting. We also highlight recent advances and discuss evidence gaps.