When to transfuse and how much in hematologic malignancies

The two main blood components commonly transfused to patients with hematologic malignancies are red cells and platelets. A number of randomized-controlled trials (RCTs) have been conducted to inform safe and effective use of platelets. The ready availability of platelet concentrates has undoubtedly made a major contribution to the supportive management of thrombocytopenic bleeding. But the optimal use of prophylactic platelet transfusions for the prevention of hemorrhage remains controversial. Two RCTs of prophylactic platelet transfusions have recently been completed in adults with thrombocytopenia due to hematologic malignancies or their treatment. Both found a no-prophylaxis approach led to higher rates of World Health Organization (WHO) grade 2-4 bleeding overall. There is ongoing discussion about whether the effectiveness of prophylactic platelet transfusions may differ between sub-groups of patients with hematologic malignancies, and whether a no-prophylaxis approach is non-inferior to prophylactic platelet transfusions in autologous hematopoietic stem cell transplantation. In contrast to use of platelets, there is very little evidence available to direct optimal use of red cells in patients with hematologic malignancies. Many patients with myelodysplasia will become red blood cell transfusion-dependent during the course of the disease, but few data exist to inform the optimal transfusion threshold and target hemoglobin concentration that translate into a significantly improved quality of life for these patients. Learning goals At the conclusion of this activity, participants should be aware that: - recent trials have started to address fundamental issues of effectiveness for use of a blood component (platelets) by comparison to a no-transfusion policy for inpatients receiving therapy for hematologic malignancies; - the results of 2 recent randomized trials have indicated that prophylactic platelet transfusions overall reduced bleeding rates in patients; - there is evidence that the effectiveness of prophylactic platelet transfusions may differ between sub-groups of patients with hematologic malignancies. Further research is necessary to establish whether a no-prophylaxis approach is non-inferior to prophylactic platelet transfusions in patients receiving autologous hematopoietic stem cell transplants, and whether prophylactic platelet transfusions are a (cost)-effective use of resources in these patients, and how these findings might relate to outpatients with chronic thrombocytopenia; - there is minimal evidence for the optimal use of red cells for inpatients with hematologic malignancies; - information is required on a range of key clinical outcomes, including health related quality of life (HrQoL). It is unclear whether higher hemoglobin concentration thresholds for red cell transfusion in patients with myelodysplasia might improve HrQoL.