Reduced Intensity versus Truly Nonmyeloablative Conditioning for Stem-Cell Transplant Recipients

Transplantation

Mature T-cell non-Hodgkin lymphomas (T-cell NHL) are a heterogeneous group of lymphoid malignancies including NK/T-cell lymphomas. Hematopoietic cell transplantation (HCT) is an important component of the management of T-cell NHL; however, the optimal timing and type of transplant for each different subtype is an ongoing debate. For the purpose of this chapter, PTCL will be classified as (1) systemic PTCL that includes nodal as well as non-nodal histologies in PTCL (2) CTCL-or cutaneous T-cell lymphomas that arise primarily in the skin and (3) NK/T-cell lymphomas both nasal and extranasal types. It is difficult to do any large trials in PTCL as they are rare diseases with variable clinical and biological characteristics and most patients are not transplant eligible due to various reasons including poor disease control. There are no randomized trials in transplant for PTCL but there is an experience based on retrospective as well as some well-designed prospective trials that have helped outline the role of HSCT in the treatment paradigm of PTCL. High-dose therapy and autologous HCT is recommended in first complete remission for most systemic (non-cutaneous) nodal subtypes, or peripheral T-cell lymphomas (PTCL). Autologous HCT can provide long-term remission for relapsed PTCL but is ineffective for refractory/chemoresistant disease. Allogeneic stem cell transplantation harnesses the graft-versus-lymphoma effect, providing long-term remission for relapsed PTCL. AlloHCT is also being used successfully to provide long-term disease control for advanced cutaneous T-cell lymphoma (CTCL). The use of transplant in NK/T-cell lymphoma is increasingly being recommended in the relapsed setting only as there are more effective treatments available for the upfront setting in limited stage disease.

High-resolution HLA matching in hematopoietic stem cell transplantation: a retrospective collaborative analysis

HLA mismatches at the allele and antigen level (possibly with the exception of HLA-DQB1) should be treated equally in donor selection. HLA mismatches at >1 locus (including HLA-DQB1) have additive detrimental effects.

Results of genoidentical hemopoietic stem cell transplantation with reduced intensity conditioning for acute myelocytic leukemia: higher doses of stem cells infused benefit patients receiving transplants in second remission or beyond--the Acute Leukemia Working Party of the European Cooperative Group for Blood and Marrow Transplantation

PURPOSE

Nucleated cell dose is an important and modifiable factor in hematopoietic stem cell transplantation (HSCT), however its association with outcomes in the context of reduced intensity conditioning regimen (RIC) HSCT for adults with acute myelocytic leukemia (AML) is not known.

PATIENTS AND METHODS

From 1998 to 2003, 253 patients with de novo AML, received transplants with RIC and peripheral blood from a genoidentical donor. Median age was 55 years (range, 18 to 72) and the median follow-up was 17 months (range, 2 to 67). One hundred forty one patients received transplants in first remission (CR1), 47 received transplants in second remission (CR2), and 65 patients received transplants in a more advanced phase. Fludarabin-based RIC was used in 91% of patients and low-dose (< 4 Gy) total-body radiation in 23% of patients. The median nucleated and CD34 cell dose infused were 9.1x 10(8)/kg and 5.8x 10(6)/kg, respectively.

RESULTS

Overall, 2-year leukemia-free survival (LFS) was 41% +/- 4% and it was 46% +/- 5% for patients receiving a higher cell dose (> 9.1x 10(8)/kg) and 37% +/- 5% for the remainders (P = .03). Higher cell doses exclusively benefited patients who received transplantations in CR2 or beyond, with LFS of 47 +/- 8 versus 20 +/- 8, with no detectable effect for patients who received transplants in CR1. In a multivariate analysis of the overall patient population, higher nucleated cell dose cells were associated with higher LFS (P = .04), higher incidence of chronic graft-versus-host disease (P = .01), and there was a trend towards a lower relapse incidence (P = .06). Interestingly, CD34+ cell dose was not associated with any outcomes.

CONCLUSION

Nucleated cell dose is an important factor that can be modified to improve results of RIC for patients with AML transplanted later than in CR1.

Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic haematopoietic stem cell transplantation for patients older than 50 years of age with acute myeloblastic leukaemia: a retrospective survey from the Acute Leukemia Working Party (ALWP) of the European group for Blood and Marrow Transplantation (EBMT)

Results of reduced intensity conditioning regimen (RIC) in the HLA identical haematopoietic stem cell transplantation (HSCT) setting have not been compared to those after myeloablative (MA) regimen HSCT in patients with acute myeloblastic leukaemia (AML) over 50 years of age. With this aim, outcomes of 315 RIC were compared with 407 MA HSCT recipients. The majority of RIC was fludarabine-based regimen associated to busulphan (BU) (53%) or low-dose total body irradiation (24%). Multivariate analyses of outcomes were used adjusting for differences between both groups. The median follow-up was 13 months. Cytogenetics, FAB classification, WBC count at diagnosis and status of the disease at transplant were not statistically different between the two groups. However, RIC patients were older, transplanted more recently, and more frequently with peripheral blood allogeneic stem cells as compared to MA recipients. In multivariate analysis, acute GVHD (II-IV) and transplant-related mortality were significantly decreased (P=0.01 and P<10(-4), respectively) and relapse incidence was significantly higher (P=0.003) after RIC transplantation. Leukaemia-free survival was not statistically different between the two groups. These results may set the grounds for prospective trials comparing RIC with other strategies of treatment in elderly AML.