Cancer-associated thrombosis and drug-drug interactions of antithrombotic and antineoplastic agents.

Venous thromboembolism (VTE) is often associated with malignant diseases and notably contributes to morbidity and mortality in patients with cancer. Cancer-associated thrombosis (CAT) brings additional costs to health expenditures and has a negative impact on oncological outcomes. Either the recurrence rate of VTE or bleeding complications are also higher in patients with cancer. Prophylactic anticoagulation has been recommended in peri-surgical periods, inpatient settings, and high-risk ambulatory patients. Although various risk stratification scores are used, none are ideal for identifying patients who can benefit from anticoagulant prophylaxis. New risk scoring systems or biomarkers are needed to identify patients who are more likely to benefit from prophylaxis with low bleeding risk. The questions about the patients who will be given prophylaxis and those who develop thromboembolism, with which drug, and how long they will be treated are still not fully answered. Anticoagulation is the cornerstone of the treatment, but management of CAT remains complex. Low molecular weight heparins and direct oral anticoagulants are effective and safe options for the treatment of CAT. Recognizing adverse effects, drug-drug interactions, and accompanying conditions that cause dose adjustment is crucial. Prevention and treatment of VTE in patients with cancer require a multidisciplinary and patient-based approach. PLAIN LANGUAGE SUMMARY: Cancer-associated thrombosis is a significant cause of mortality and morbidity in patients with cancer. Chemotherapy, surgery, and/or use of central venous access remarkably increase the risk of thrombosis. Prophylactic anticoagulation should be considered not only in inpatient follow-up and during peri-surgical period but also ambulatory patients with a high risk of thrombosis. Many parameters, such as drug-drug interactions, primary side of cancer, and comorbidities of patients should be considered when selecting anticoagulant drugs. More accurate risk stratification scores or biomarkers are still an unmet need.