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Haematologica 2020 Volume 105(3):838-848
Coagulation & its Disorders
Updated meta-analysis on prevention of venous thromboembolism in ambulatory cancer patients
Cecilia Becattini,1 Melina Verso,1 Andres Muňoz2 and Giancarlo Agnelli1
1Internal and Cardiovascular Medicine – Stroke Unit, University of Perugia, Perugia, Italy and 2Hospital General Universitario Gregorio Marañón, Madrid, Spain
ABSTRACT
Randomized clinical trials have evaluated the role of anticoagulants in the prevention of venous thromboembolism (VTE) in ambulatory cancer patients treated with chemotherapy. This meta-analysis is aimed at providing an updated evaluation of the efficacy and safety of anti- coagulant prophylaxis in this clinical setting. Medline and Scopus were searched to retrieve randomized controlled trials on the prevention of VTE in ambulatory cancer patients. Two groups of trials were identified with VTE or death as the primary outcome, respectively. VTE was the primary outcome of this analysis. Anticoagulant prophylaxis reduced the incidence of VTE in studies in which the primary outcome was VTE [14 studies, 8,226 patients; odds ratio (OR)=0.45; 95% confidence interval (95% CI): 0.36- 0.56] or death (8 studies, 3,727 patients; OR=0.61; 95% CI: 0.47-0.81). When these studies were pooled together, VTE was reduced by 49% (95% CI: 0.43-0.61) with no significant increase in major bleeding (OR=1.30, 95% CI: 0.98-1.73). The risk of major bleeding was increased in studies with VTE as the primary outcome (OR=1.43, 95% CI: 1.01-2.04). Similar reductions of VTE were observed in studies with parenteral (OR=0.43, 95% CI: 0.33- 0.56) or oral anticoagulants (OR=0.49, 95% CI: 0.33-0.74). The reduction in VTE was confirmed in patients with lung (OR=0.42, 95% CI: 0.26-0.67) or pancreatic cancer (OR=0.26, 95% CI: 0.14-0.48), in estimated high-risk patients, in high-quality studies and with respect to symptomatic VTE. In conclusion, prophylaxis with oral or parenteral anticoagulants reduces the risk of VTE in ambulatory cancer patients, with an acceptable increase in major bleeding.
Introduction
The risk of venous thromboembolism (VTE) is four to seven times higher in patients with cancer than in individuals without this disease.1,2 The high incidence of cancer-associated thrombosis is probably related to a combination of the intrin- sic prothrombotic activity of cancer cells, aggressive chemotherapy treatment, aging of cancer patients, and enhanced VTE detection owing to improvements in imaging technology and frequency of imaging.3-5 Anti-cancer therapies, either tra- ditional chemotherapy, hormones or biological agents, can potentially increase the risk of VTE up to an annual rate of 15%, depending on the type and combination of agents, or the addition of radiotherapy.6 Survival of cancer patients has been sig- nificantly improved in recent times and this increases the time of risk exposure for VTE in cancer patients.
Based on these epidemiological data, several studies have been conducted aimed at assessing the role of anticoagulants in preventing VTE in ambulatory can- cer patients treated with chemotherapy. These studies showed that prophylaxis with anticoagulants reduced the risk of VTE by about 50%, with no significant increase in the risk of major bleeding.7 However, the use of prophylaxis remains controversial because of concerns over the relatively low incidence of VTE in these patients, the risk-to-benefit ratio, the cost and the inconvenience of prolonged par- enteral therapy. As a consequence, antithrombotic prophylaxis is still not recom-
Correspondence:
CECILIA BECATTINI
cecilia.becattini@unipg.it
Received: March 7, 2019. Accepted: June 6, 2019. Pre-published: June 6, 2019.
doi:10.3324/haematol.2019.221424
Check the online version for the most updated information on this article, online supplements, and information on authorship & disclosures: www.haematologica.org/content/105/3/838
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