UCBT Using Myeloablative Conditioning Regimen without ATG Has Similar Survival but Better Life Quality Compared with Upbsct for Adults with Primary Acute Leukemia-a Multicenter Study in China

Objective

Data regarding the outcome of unrelated cord-blood transplantation (UCBT) with myeloablative conditioning regimen without ATG comparing with unrelated peripheral blood stem cell transplantation (UPBSCT) for adults with primary acute leukemia.

Methods

From Jan 2010 to Dec 2014, 175 consecutive adult patients with primary acute leukemia (AL), who had no HLA-compatible related donors who were eligible for a single UCBT (79 patients) or UPBSCT (96 patients). The two groups all received a TBI/CY2 and BU/CY2 based myeloablative conditioning regimen which plus fludarabine (FLU), etoposide (VP-16) or cytarabine (Ara-c). The GVHD prophylaxis regimens of UCBT were cyclosporine A (CsA) and mycophenolate mofetil (MMF) and UPBSCT were CsA, Methotrexate (MTX) and antithymocyte globulin (ATG).

Results

There was no significant difference for the patients characteristics between the UCBT and UPBSCT group except for UCBT patients were younger. Although the UCBT patients received lower doses of nucleated and CD34 positive cells and more patients were HLA mismatched, the two groups acquired the similar percentage of hematopoiesis engraftment rate (97.4% vs 100%, p=0.497) but the granulocyte and platelet recovery was slower in UCBT group. The incidence of bacterial or invasive fungal infection in the UCBT group and the UPBSCT group had no significant difference (46.8% vs 52.6%, P=0.572) may be attributed to the omission of ATG in UCBT group. TRM by three years was 21.0% and 16.9% in the UCBT and UPBSCT cohorts (P=0.46). The 3-year cumulative incidence of relapse was similar between the UCBT group and the UPBSCT group (26.3% vs 27.1%, P=0.75). The grade II to IV acute graft-versus-host disease (aGVHD) and severe aGVHD (grades III and IV) incidence was similar between the two groups (24.7% vs 33.0%, P=0.40), (13.3% vs 8.7%, P=0.28)]. Compared with the UPBSCT cohort, the UCBT cohort had a significantly lower rate of chronic graft-versus-host disease (cGVHD) (20.7% vs 44.0%, p=0.003) or extensive cGVHD (5.6% versus 17.5%, P=0.04). The overall survival (63.2% vs 64.1%, P=0.996) and leukemia free survival (57.5% vs 59.8%, P=0.824) had no significant difference between the two groups. The performance status observed in patients surviving 3 years was measured using the Karnofsky performance score. The UCBT recipients had obviously higher activity scores than UPBSCT recipients (94.5% vs 83.5%, p=0.03).

Conclusion

When use intensive myeloablative conditioning regimen without ATG, UCBT can reach similar survival with UPBSCT and may have better life quality. Primary acute leukemia patients who lack an HLA-matched sibling donor can select UCBT or the UPBSCT of equal status.