Effect of Treatment with Epoetin Beta on Thromboembolic Events in Anemic Patients with Cancer: A Metaanalysis

Epoetin therapy is associated with a slight increase in thromboembolic event (TEE) incidence, although causality is uncertain. This metaanalysis compared TEE incidence in patients with cancer-related anemia treated with epoetin beta versus a control group (placebo or standard treatment) and investigated the impact of hemoglobin (Hb) parameters on thromboembolic risk. Patients from 9 randomized trials were pooled (epoetin beta group, n = 800; control group, n = 613). Adverse event reports were reviewed for all TEEs recorded during treatment and 28 days thereafter. Thromboembolic event incidence was compared between 2 groups, and standard statistical analyses were conducted to investigate the potential of Hb parameters to modulate thromboembolic risk. For epoetin beta, 5.9% of patients (n = 47) experienced ≥ 1 TEE versus 4.2% of controls (n = 26; not significant). Thromboembolic-related mortality rates were 1% in both groups. Thromboembolic event rates in patients stratified by tumor type were consistent with the overall population. For epoetin beta, greater baseline-adjusted Hb area under the concentration-time curve and greater Hb increases during the first 4 weeks of treatment significantly correlated with reduced risk of TEEs. Conversely, treatment in those with higher baseline Hb levels was associated with increased TEE risk. When administered in accordance with European Organization for Research and Treatment of Cancer guidelines, epoetin beta did not appear to be associated with increased thromboembolic risk. Although risk of TEEs might be marginally increased in patients with cancer treated with epoetin beta, there is no increased risk of thromboembolic mortality.