The frequency of venous thromboembolism (VTE) is rising in patients with cancer. VTE contributes to mortality and morbidity, but the risk for VTE can vary widely between individual patients. Clinical risk factors for VTE in cancer include primary site of cancer, use of systemic therapy, surgery, and hospitalization. Biomarkers predictive of VTE include platelet and leukocyte counts, hemoglobin, D-dimer, and tissue factor. A recently validated risk model incorporates 5 easily available variables and can be used clinically to identify patients at increased risk of VTE. In high-risk settings, including surgery and hospitalization, thromboprophylaxis with either unfractionated heparin or low-molecular-weight heparins has been shown to be safe and effective. Recent studies have also suggested a potential benefit for thromboprophylaxis in the ambulatory setting, although criteria for selecting patients for prophylaxis are not currently well defined. This article focuses on recent and ongoing studies of risk assessment and prophylaxis in patients with cancer.
Alok A. Khorana
Alok A. Khorana
Venous thromboembolism (VTE) has serious consequences for patients with cancer, including mortality. VTE is preventable with appropriate thromboprophylaxis, but prior public health efforts have focused on prophylaxis in the inpatient setting. However, most VTE events in malignancy currently occur in outpatients. Several recent clinical trials have addressed thromboprophylaxis in the ambulatory setting. Their findings suggest potential benefit, but with significant variation in underlying risk. A risk-adapted approach that incorporates risk of thrombosis, risk of bleeding, and patient preference can target high-risk patients and also allow low-risk patients to avoid prophylaxis. Risk assessment is therefore key to patient selection for outpatient prophylaxis. This article focuses on results of recent trials and updates from major guideline panels, with the intent of providing guidance to clinical providers.