Page 331 - Haematologica March 2020

Prevention of VTE in cancer patients
A
Figure 2. Efficacy of anticoagulant prophylaxis for the prevention of venous thromboembolism (VTE) in ambulatory cancer patients receiving chemotherapy in studies with VTE as the primary outcome. (A) Efficacy for the prevention of symptomatic VTE. (B) Efficacy for the prevention of fatal VTE.
B
patients.44 Even though no consensus exists on the opti- mal strategy to identify ambulatory cancer patients at high risk of a first VTE,45 the Khorana approach was fol- lowed in the two recent studies.11,12 While the efficacy of anticoagulant prophylaxis was confirmed in this analy- sis, the incidence of VTE in the placebo arms in these two trials was 10%. Whether this incidence is high enough to recommend anticoagulant prophylaxis is con- troversial.
Our study has several limitations in addition to those intrinsic to a meta-analytic approach, which combines heterogeneous datasets. For example, the heterogeneity in the incidence of VTE was not resolved after excluding an outlier study in children receiving asparaginase20 and was also related to recent studies that specifically includ- ed patients at high risk of VTE. The inclusion of screen- ing-detected or incidental VTE in the primary outcome could be a further determinant of heterogeneity. It
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