Impact of Disease Status on Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation with Refractory and Relapsed Acute Lymphoblastic Leukemia

Objective: To evaluate the impact of disease status on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of patients with refractory and relapsed acute lymphoblastic leukemia(ALL).

Methods: 52 patients with refractory and relapsed ALL, including 19 cases in advanced stage (nonremission, NR) and 33 cases in more than or equal to second complete remission(≥CR2), received allo-HSCT after myeloablative conditioning regimen in our department.

Results: 51 patients engrafted successfully. The transplantation-related mortality (TRM) rate of NR and ≥CR2 was 10.5% vs 12.1% (P=0.815). The incidence of aGVHD was 52.6% vs 57.6% (P=0.730), including 42.1% vs 33.3% (P=0.527) with mild (grade I-II) and 10.5% vs 24.3% (P=0.399) with severe (grade III-IV) aGVHD. The incidence of cGVHD was similar also(41.6% vs 57.9% ,P=0.660). With a median follow-up of 12(1.8-44.5) months, the cumulative relapse rate of NR and ≥CR2 was 47% vs 34.3% (P=0.425) respectively. The estimated 2 year overall survival (OS) and 2 year leukemia-free survival (LFS) rate were 42.6% vs 45.7% (P=0.487) and 46.3% vs 46.2% (P=0.571) respectively. Multivariate Analysis results showed that cGVHD was independent favorable risk factor for OS and LFS of R/R ALL. For relapsed patients, OS was significantly better with first CR duration>6 month and time to transplant≤2 months.

Conclusion: AlIo-HSCT is an effective salvage treatment option for patients with refractory and relapsed ALL. Our retrospective analysis showed that R/R ALL with different status prior transplant had similar outcome post transplantation.