Inpatient prophylaxis in cancer patients: where is the evidence?

Venous thromboembolism (VTE) is a leading cause of preventable in-hospital mortality. Cancer is associated with an increased risk of VTE which is further compounded by acute hospitalization for medical illness. The absolute incidence of VTE of hospitalized cancer patients ranges between 2% and 17% but the rates vary considerably depending on the type of study, method of VTE surveillance and whether pharmacologic thromboprophylaxis is administered. Complicating the interpretation of thromboprophylaxis trials is the paucity of reported data on the relative benefit of thromboprophylaxis relative to an increased risk of hemorrhage inherent to cancer patients. Efforts over the last decade have improved the rates of adherence to in-hospital pharmacologic thromboprophylaxis regimens. Whether these efforts also improve outcomes continues to be debated. In this review, the prevalence of VTE and hemorrhage in hospitalized cancer patients is presented in the context of pharmacologic thromboprophylaxis data along with a discussion of emerging approaches towards VTE risk-adapted prescription of antithrombotics during hospitalization.