Summary
Cancer patients are at increased risk of developing venous thromboembolism (VTE).
Guidelines recommend routine thromboprophylaxis in hospitalised acutely ill cancer
patients and in myeloma patients receiving combination treatments including thalidomide
or lenalidomide. Currently, thromboprophylaxis is not recommended in cancer out-patients.
It is the aim of this review to give an overview of studies that applied scores for
the risk assessment of cancer-related VTE. We will also discuss randomised controlled
trials (RCTs) that investigated primary thromboprophylaxis in cancer patients. Recently,
Khorana et al. published a practical and reproducible risk assessment score that includes
clinical and laboratory parameters for the stratification of cancer patients according
to their propensity to develop VTE. Patients assigned to the high-risk group are likely
to benefit most from primary thromboprophylaxis. This score was validated in prospective
and retrospective observational studies. In the Vienna Cancer and Thrombosis Study
(CATS) the score was expanded by adding two biomarkers, and the prediction of VTE
was considerably improved. In recent RCTs including cancer patients with different
malignancies it was shown that thromboprophylaxis is safe and effective. However,
VTE incidence rates were low. To date, no data is available from interventional studies
applying thromboprophylaxis in cancer patients categorised into high-risk groups on
the basis of risk assessment with scores. From the available literature we conclude
that risk assessment for VTE is feasible in cancer patients;however, interventional
studies to investigate the safety and efficacy of thromboprophylaxis in a high risk
cancer population have yet to be performed.
Keywords
Cancer - venous thrombosis - risk assessment - randomised controlled trials