Emerging risk stratification approaches to cancer-associated thrombosis: risk factors, biomarkers and a risk score

Cancer patients are well-known to be at increased risk of venous thromboembolism (VTE). However, the risk varies widely between patients and over the natural history of malignancy. Recent data have identified multiple clinical risk factors as well as biomarkers predictive of VTE. Risk factors include patient-associated factors such as age, obesity and medical comorbidities, cancer-associated factors such as site and stage of cancer, and treatment-associated factors, particularly chemotherapy and anti-angiogenic therapy. Biomarkers associated with increased risk of cancer-associated VTE include leukocyte count, platelet count, and levels of tissue factor, P-selectin and D-dimer. This review focuses on the evidence for risk stratification of cancer patients, based on these risk factors and biomarkers, as well as a recently validated predictive model which can be used to identify patients at highest risk. Targeted thromboprophylaxis utilizing model-based and/or biomarker-based approaches may provide an optimal risk-benefit ratio and is currently the focus of ongoing clinical trials.