Clinical Challenges in Treating Cancer Associated Thrombosis: A Clinically Oriented Review.

Background: Managing cancer associated thrombosis (CAT) is a significant clinical challenge due to several factors such as increased bleeding tendency, frailty, and drug - drug interactions. For many years, the drug of choice for treating CAT was low molecular weight heparin (LMWH); Recently, direct oral anticoagulants (DOACs) entered to the therapeutic milieu of CAT. However, due to the large diversity among patients with CAT in clinical and laboratory characteristics not all patients will equally benefit from treatment with DOACs. Furthermore, several subgroups of patients with CAT have specific characteristics that influence the anticoagulant decision-making process.

Summary: In this review, we present four different theoretical clinical case scenarios, each representing a different challenge that is associated with thrombosis management; brain metastasis, malignancies of the gastrointestinal tract, drug-drug interactions (DDI) and thrombocytopenia. By reviewing current literature, we suggest our clinical approach for managing these cases in the era of DOACs.

Key Messages: (1) The management of patients with brain tumors and CAT is challenging due to increased risk for both intracranial hemorrhage and recurrent venous thromboembolism (VTE). Both LMWH and DOACs are optional treatment in this setting. (2) There are conflicting data regarding the bleeding risk in patients with GI malignancies. Treatment with LMWH should be considered specifically in patients with advanced disease and unresectable tumors. (3) There is a paucity of data regarding DDI in patients with CAT. However, caution should be exercised when prescribing DOACs to patients receiving concurrent medications that either affect DOAC metabolism or influence bleeding risk. (4) The management of patients with CAT and thrombocytopenia depends on the severity of thrombocytopenia and the timing of the thrombotic event.