haematology and oncology
Perspectives for treating
cancer-associated thrombosis
Fixed-dose treatment with the novel direct oral anticoagulants is likely to replace subcutaneous
low-molecular-weight heparins for most cancer patients with venous thromboembolism
Paolo Prandoni
MD PhD
Andrea Piccioli
MD PhD
Arianna Foundation
on Anticoagulation,
Bologna, Italy
It is well known that patients with cancer-
associated thrombosis (CAT) have a risk of both
venous and arterial thrombotic complications,
which exceeds by far that expected in the general
population. 1 These vascular complications prevail
in patients with the most advanced stages of
cancer, and are often life-threatening. 1 Indeed,
pulmonary embolism (PE) is the second most
common cause of death in patients with CAT,
soon after mortality induced by cancer itself. 1
Although venous thromboembolism (VTE) is often
triggered by identifiable risk factors (such as
surgical operations, central or peripheral venous
catheters, chemotherapy or long-standing
immobilisation) either alone or in various
combinations, VTE complications often arise
spontaneously, making it virtually impossible to
either predict or prevent their development. 2
Conventional treatment
When VTE episodes develop in patients with
cancer, they are often resistant to conventional
treatment. It has, indeed, been shown
conclusively that the rate of symptomatic
recurrent VTE in CAT while on (even correct)
treatment with vitamin K antagonists (VKA)
exceeds that expected in patients without cancer
by 3–4-times. 3 Unfortunately, the rate of major
bleeding complications increases as well, making
increasing the intensity of VKA therapy
unsuitable. 3
Low-molecular weight heparins
A number of randomised clinical trials,
performed in the last ten years, have conclusively
demonstrated that the initial and long-term
treatment of CAT with therapeutic or slightly
sub-therapeutic subcutaneous doses of low-
molecular weight heparins (LMWHs) is associated
with a statistically significant and clinically
relevant reduction in the risk of subsequent
symptomatic recurrent VTE over VKA with
a comparable risk of major bleeding. 1,4–7 Their
use, however, leads to a considerable burden
for patients and a considerable cost for health
care systems. They are, indeed, much more
expen