Incidence, risk factors, and management of bleeding in patients receiving anticoagulants for the treatment of cancer-associated thrombosis

Updated clinical practice guidelines recommend the long-term use of low-molecular-weight heparins or direct oral anticoagulants as the preferred option for the treatment of cancer-associated thrombosis (CAT), using a personalized approach matching the right drug to the right patient. In most cases, the benefit of anticoagulant therapy outweighs the risk. However, the long-term use of anticoagulants is associated with a non-negligible risk of bleeding, which constitutes a rare but serious adverse effect. Bleeding complications have been reported to be overall 2 to 3 times more frequent in cancer patients with CAT receiving anticoagulation than in non-cancer patients, with a reported incidence of major bleeding ranging from 2.4 to 16.0% in randomized controlled trials (RCT). In the absence of validated risk assessment model to predict the risk of bleeding in these patients, a careful evaluation of each individual profile, with adequate selection of the most appropriate anticoagulant for each individual patient, is warranted for overcoming management challenges, taking in account the numerous factors which may potentiate the overall bleeding risk in these complex patients, such as advanced or metastatic disease, older age, anemia, thrombocytopenia, renal impairment, liver dysfunction, and concomitant anticancer therapies. The purpose of this review is to call for awareness on bleeding complications as a major safety issue of CAT treatment and to summarize data from recent RCT and real-world studies on the incidence and risk factors for bleeding in this unique and challenging population to further help clinicians in decision-making.