SUMMARY: The ASCO convened an Expert Panel and updated evidence-based guidance on the use of platelet transfusion in patients with cancer. This guideline updates is based on a systematic review of the medical literature published from September 1, 2014, through October 26, 2016 and this review builds on two 2015 systematic reviews that were conducted by the AABB and the International Collaboration for Transfusion Medicine Guidelines. This ASCO guideline replaces the previous ASCO platelet transfusion guideline published initially in 2001. The updated ASCO review included 24 more recent publications which included 3 clinical practice guidelines, 8 systematic reviews, and 13 observational studies.
Target Population: Adults and children (4 months of age or older) with hematologic malignancies, solid tumors, or hypoproliferative thrombocytopenia.
Target Audience: Clinician’s administering intensive therapies to patients with cancer.
Clinical Questions and Recommendations:
(1) How should platelets for transfusion be prepared?
Platelets can be prepared either by separation of units of platelet concentrates from whole blood using either the buffy coat or the platelet-rich plasma method, which can then be pooled before administration, or by apheresis from single donors. Studies have shown that the post-transfusion increments, hemostatic benefit, and adverse effects are similar with any of these platelet products and they can be used interchangeably. However, single-donor platelets from selected donors are necessary when histocompatible platelet transfusions are needed.
(2) In what circumstances should providers take steps to prevent Rh alloimmunization resulting from platelet transfusion?
Prevention of RhD alloimmunization resulting from platelet transfusions to RhD-negative recipients can be achieved either through the exclusive use of platelet products collected from RhD-negative donors or via anti-D immunoprophylaxis. These approaches may be used for female children and female adults of child-bearing potential being treated with curative intent. However, because of the low rate of RhD alloimmunization in patients with cancer, these approaches need not be applied universally.
(3) In what circumstances should providers use leukoreduced blood products to prevent alloimmunization?
Providing leukoreduced blood products to patients with Acute Myeloid Leukemia from the time of diagnosis is appropriate, as the incidence of alloantibody-mediated refractoriness to platelet transfusion can be decreased in patients receiving induction chemotherapy, when both platelet and RBC products are leukoreduced before transfusion. It is likely that alloimmunization can also be decreased in patients with other types of leukemia and in other patients with cancer who are receiving chemotherapy. The same holds true for patients with Aplastic Anemia, and Myelodysplasia not receiving chemotherapy, in the same time periods that the transfusions are being administered. In the United States and in several other countries, majority of blood products are leukoreduced at the time of blood collection and component preparation. Prestorage leukoreduction can result in a substantial reduction in transfusion reactions and in transmission of cytomegalovirus (CMV) infection
(4) Should platelet transfusions be given prophylactically or therapeutically?
Prophylactic platelet transfusion should be administered to patients with thrombocytopenia resulting from impaired bone marrow function to reduce the risk of hemorrhage, when the platelet count falls below a predefined threshold level. This threshold level for transfusion varies according to the patient’s diagnosis, clinical condition, and treatment modality.
(5) What is the appropriate threshold for prophylactic platelet transfusion in patients with hematologic malignancies?
The Panel recommends a threshold of less than 10×109/L for prophylactic platelet transfusion in patients receiving therapy for hematologic malignancies. Transfusion at higher levels may be advisable in patients with signs of hemorrhage, high fever, hyperleukocytosis, rapid fall of platelet count, or coagulation abnormalities (eg, acute promyelocytic leukemia) and in those undergoing invasive procedures or in circumstances in which platelet transfusions may not be readily available in case of emergencies, as might be the case for outpatients who live at a distance from the treatment center.
(6) What is the appropriate threshold for prophylactic platelet transfusion in the setting of Hematopoietic Stem Cell Transplantation (HSCT)?
The Panel recommends a threshold of less than 10×109/L for prophylactic platelet transfusion in adult and pediatric patients undergoing allogeneic HSCT. Prophylactic platelet transfusion may be administered at higher counts based on clinician judgment. In adult recipients of autologous HSCT, randomized trials have demonstrated similar rates of bleeding with decreased platelet usage when patients are transfused at the first sign of bleeding rather than prophylactically, and this approach may be used in experienced centers. This recommendation is not generalizable to pediatric patients.
(7) Is there a role for prophylactic platelet transfusion in patients with chronic, stable, severe thrombocytopenia who are not receiving active treatment?
Patients with chronic, stable, severe thrombocytopenia, such as individuals with Myelodysplasia or Aplastic Anemia, who are not receiving active treatment may be observed without prophylactic transfusion, reserving platelet transfusions for episodes of hemorrhage or during times of active treatment.
(8) What is the appropriate threshold for prophylactic platelet transfusion in patients with solid tumors?
The risk of bleeding in patients with solid tumors during chemotherapy-induced thrombocytopenia is related to the depth and duration of the platelet nadir, although other factors contribute as well. The Panel recommends a threshold of less than 10×109/L for prophylactic platelet transfusion. Platelet transfusion at higher levels is appropriate in patients with active localized bleeding, which can sometimes be seen in patients with necrotic tumors.
(9) At what platelet count can surgical or invasive procedures be performed?
The Panel recommends a threshold of 40×109/L to 50×109/L for performing major invasive procedures in the absence of associated coagulation abnormalities. Certain procedures, such as bone marrow aspirations and biopsies, and insertion or removal of central venous catheters, can be performed safely at counts 20×109/L or more. If platelet transfusions are administered before a procedure, it is critical that a post-transfusion platelet count be obtained to prove that the desired platelet count level has been reached. Platelet transfusions should also be available on short notice, in case intraoperative or postoperative bleeding occurs. For alloimmunized patients, histocompatible platelets must be available in these circumstances.
(10) When and how should patients be monitored for refractoriness to platelet transfusion?
The Panel recommends that when refractoriness is suspected, platelet counts should be performed 10-60 minutes after transfusion. Because patients may have a poor increment to a single transfusion and yet have excellent platelet increments with subsequent transfusions, a diagnosis of refractoriness to platelet transfusion should only be made when at least two transfusions of ABO-compatible units, stored for less than 72 hours, result in poor increments (less than 5000/microliter).
(11) How should refractoriness to platelet transfusion be managed?
Alloimmunization is usually due to antibody against HLA antigens and only rarely to platelet-specific antigens. Patients with alloimmune-refractory thrombocytopenia, as defined previously, are best managed with platelet transfusions from histocompatible donors matched for HLA-A and HLA-B antigens. For patients( 1) whose HLA type cannot be determined, (2) who have uncommon HLA types for whom suitable donors cannot be identified, or (3) who do not respond to HLA-matched platelets, histocompatible platelet donors can often be identified using platelet cross-matching techniques. In many patients, these two techniques are complementary.
Platelet Transfusion for Patients With Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update. Schiffer CA, Bohlke K, Delaney M, et al. J Clin Oncol. 2017 Nov 28:JCO2017761734. doi: 10.1200/JCO.2017.76.1734. [Epub ahead of print]
