Primary prophylaxis of VTE in cancer outpatients.

Cancer patients have a significantly higher risk of developing venous thromboembolism (VTE) compared to non-cancer patients and several studies suggest that VTE risk among ambulatory cancer patients varies widely. Recently, predictive models capable of risk-stratifying a broad range of ambulatory cancer outpatients have been developed and validated; using the Khorana model a score of 2 is associated with an intermediate-high risk for VTE. However, the use of VTE prophylaxis in ambulatory patients who have cancer remains controversial. Even if important randomized clinical trials showed decreased rates of VTE events among patients who were receiving chemotherapy, the effect of prophylaxis on morbidity, mortality, and costs has not been rigorously studied. Outpatients with active cancer should be assessed for thrombosis risk and although most do not routinely require thromboprophylaxis, it should be considered for high risk patients.