Prophylactic platelet transfusions in patients with haematological malignancies – lessons from the TOPPS trial
People with haematological malignancies are the largest patient group who use platelet components.1 Platelet transfusions are an important supportive therapy during treatment with chemotherapy or haematopoietic stem cell transplantation (HSCT).2 Guidelines recommend that platelet transfusions be given to people with hypoproliferative thrombocytopenia to reduce the risk of spontaneous bleeding when platelet count <10x109/L.2,3 This means the majority of people receiving treatment for a haematological malignancy will receive at least one platelet transfusion. The Trial of Prophylactic Platelets (TOPPs) trial was a randomised controlled trial that compared a no-prophylaxis versus prophylaxis platelet transfusion regimen.4 Overall, a no-prophylaxis approach led to higher rates ofWorld Health Organization (WHO) grade 2–4 bleeding. However, a prespecified subgroup analysis found that the reduction in the proportion of patients experiencing WHO grade 2–4 bleeds seen in the prophylaxis arm was larger in people receiving chemotherapy or an allogeneic HSCT (chemo/alloHSCT) than in people receiving an autologous HSCT (autoHSCT) (test for interaction P =0.04).5 Analysis of secondary outcomes showed a shorter time to first bleeding episode with no-prophylaxis in the chemo/alloHSCT subgroup compared to the autoHSCT subgroup, but a similar increase in the number of days with WHO grade 2–4 bleeding in both subgroups in the no-prophylaxis study arm. Multivariate recurrent event analyses of TOPPS trial data investigated patient factors and clinical characteristics associated with bleeding.6 Baseline characteristics associated with an increased hazard of WHO grade 2–4 bleeding were: study arm (no-prophylaxis); female sex, and type of treatment (chemo/alloHSCT). Other significant factors were the number of days with a platelet count <10 x 109/L, and fever (≥38 ∘C). There is evidence that the effectiveness of prophylactic platelet transfusions differs between subgroups of people with haematological malignancies. There is no evidence that a prophylactic platelet transfusion policy is superior to no-prophylaxis for people receiving an autologous HSCT. REFERENCES 1. Estcourt LJ. Why has demand for platelet components increased? A review. Transfus Med 2014;24:260–8. 2. Kaufman RM, Djulbegovic B, Gernsheimer T, et al. Platelet transfusion: a clinical practice guideline from the AABB. Ann Intern Med 2015;162:205–13. 3. Padhi S, Kemmis-Betty S, Rajesh S, Hill J, Murphy MF. Blood transfusion: summary of NICE guidance. BMJ 2015;351:h5832. 4. Stanworth SJ, Estcourt LJ, Powter G, etal. A no-prophylaxis platelet-transfusion strategy for hematologic cancers. N Engl J Med 2013;368:1771–80. 5. Stanworth SJ, Estcourt LJ, Llewelyn CA, Murphy MF, Wood EM. Impact of prophylactic platelet transfusions on bleeding events in patients with hematologic malignancies: a subgroup analysis of a randomized trial. Transfusion 2014;54:2385–93. 6. Stanworth SJ, Hudson CL, Estcourt LJ, Johnson RJ, Wood EM. Risk of bleeding and use of platelet transfusions in patients with hematologic malignancies: recurrent event analysis. Haematologica 2015;100: 740–7.