Summary
In the initial treatment of venous thromboembolism (VTE) fondaparinux, a pentasaccharide,
is a good alternative to heparin. Whether this is also true for cancer patients is
unknown. We performed two post-hoc analyses of two randomized studies to compare efficacy,
safety and overall survival of fondaparinux to standard initial (low-molecular-weight)
heparin (LMWH) treatment in cancer patients with venous thromboembolism. Two hundred
thirty-seven cancer patients with deep venous thrombosis (DVT) were initially treated
with fondaparinux or enoxaparin. Two hundred forty cancer patients with pulmonary
embolism (PE) received fondaparinux or unfractionated heparin. The initial treatment
was followed by vitamin K antagonists. In DVT patients, the three-month recurrence
rate was 5.4% in the enoxaparin recipients compared to 12.7% in those treated with
fondaparinux [absolute difference 7.3%, 95% CI 0.1, 14.5]. A recurrence was observed
in 8.9% of the PE patients treated with fondaparinux compared to 17.2% in the unfractionated
heparin recipients [absolute difference –8.3, 95% CI –16.7, 0.1]. In both studies
no difference in bleeding and overall survival was observed. Regarding overall survival
and bleeding fondaparinux is comparable to enoxaparin and unfractionated heparin in
cancer patients. No significant differences in recurrent VTE were observed when comparing
fondaparinux with unfractionated or LMWH. Because of study limitations these results
should be considered hypothesis-generating.
Keywords
Venous thromboembolism - cancer - anticoagulants - heparin - pentasaccharides