| Abstract: |
Who should receive a UCBT? Currently, UCBT is a valid alternative for any patient requiring unrelated donor transplantation without a suitably matched and readily available unrelated volunteer. The MSKCC strategy for hematologic malignancies is outlined in Figure 4. In patients age < 16 years with leukemia, emerging data indicate that outcome is superior with matched UCB and comparable with 4-5/6 matched units, suggesting that UCB should take priority over BM, particularly if there is a 6/6 unit, or a 5/6 unit with a dose > 3 × 107 NCs/kg. In adults, the priority of unrelated volunteer HSCs versus UCB will depend on the strategy for preventing GVHD using unrelated volunteer HSCs (particularly in the setting of mismatch) and on the strategy for augmenting the UCB graft cell dose. Furthermore, if the patient is only a candidate for an RI or a NMA regimen, then the patient's diagnosis and previous therapy must be considered when selecting the optimal pretransplantation therapy to ensure donor engraftment. Finally, because selecting a UCB graft is more complicated than selecting an unrelated volunteer donor, transplantation at centers with UCBT expertise is ideal. Centers should be encouraged to have a written algorithm dictating the minimum criteria of cell dose and HLA match, as well as an approach to trading off dose and match, to guide search coordinators in unit selection. A randomized trial of unrelated volunteer HSC and UCB is needed. However, the logistics of such a study are challenging, and whether or not such a study will be feasible is unclear. In the meantime, transplant centers are strongly encouraged to enroll patients on either "in-house" innovative protocols or multicenter studies. Two important US multicenter studies enrolling patients with high-risk leukemia and MDS are the Blood and Marrow Transplant Clinical Trials Network study, randomizing pediatric patients to single versus double UCB units, and the Center for International Transplant Research-sponsored multicenter study of double-unit UCBT in adults. © 2007 American Society for Blood and Marrow Transplantation. |
