Disease-Free Survival Of Myelodysplastic Syndrome After Allogeneic Hematopoietic Stem Cell Transplantation Is Not Associated With Disease Status and Donor Sources
Authors: Lu Yue , Wu Tong , Cao Xing-Yu , Zhao Yan-Li , Liu De-Yan , Zhou Jia-Rui , Xiong Min , Zhang Jian-Ping , Sun Rui-Juan , Wei Zhi-Jie , Ji Shu-Quan , Lu Dao-Pei 
Published: October 2019

Abstract

Introduction
Allogeneic hematopoietic stem cell transplantation (HSCT) is an only curative modality currently for myelodysplastic syndrome (MDS). High-risk MDS usually has lower complete remission (CR) rate and higher chemotherapy-related mortality compared with de novo acute myeloid leukemia (AML). To examine whether CR before HSCT has survival benefit for MDS treated by HSCT, we retrospectively analyzed the data during 11 years from our center. The clinical outcomes of MDS after HSCT from different donor sources have also been evaluated.

Objective
In present clinical study, the effects of disease status and donor sources on disease-free survival (DFS) of MDS after HSCT were studied.

Methods
From August 2001 to December 2012, total 122 patients with MDS that underwent HSCT in our center were enrolled. Male to Female was 76: 46. The median age was 35 (8 to 57) years old. The median blasts in bone marrow (BM) before conditioning were 9% (1% to 65%). According to 2008 WHO classification, the patients were diagnosed as refractory cytopenias with unilineage dysplasia (RCUD) in 12, refractory anemia with ring sideroblasts (RARS) in 2, 5q- in 1, refractory cytopenias with multilineage dysplasia (RCMD) in 15, refractory anemia with excess blasts (RAEB) -1/RAEB-2 in 36 and transformed AML in 56. For International Prognostic Scoring System (IPSS), 12 patients were in low-risk, 27 in intermediate-1, 24 in intermediate-2, and 59 in high-risk. Based on BM blast percentage pre-conditioning, 47 cases were less than 5%, 43 patients were between 5% to 20%, and 32 cases were more than 20%. The stem cells were from identical siblings (45) or unrelated donor (24) or haploidentical family members (53). Conditioning regimens were BUCY/BUFLU for identical sibling HSCT, and BUCY/BUFLU plus ATG (Thymoglobuline, 8-10mg/kg) for unrelated or haploidentical transplants. Graft-versus-host disease prophylaxis was employed by Cyclosporin A, Methotrexate and Mycophenolate mofetil as reported previously (DP Lu et al., Blood 2006; 107:3065). Results: With median follow-up 31 (1-144) months, DFS was 73.8%. Fourteen patients (11.4%) relapsed. Transplant-related mortality was 14.8%. No significant differences on DFS were found among RCUD/RARS/5q- (68.8%), RCMD (85.7%), RAEB-1/RAEB-2 (72.2%) and transformed AML (73.2%) (p=0.761). A similar DFS was seen in different risk categories (73.3% in low-risk, 79.2% in intermediate-1, 75.0% in intermediate-2 and 71.2% in high-risk; p=0.861). Moreover, CR or not before HSCT has no remarkable effect on DFS (blasts <5%, 78.7%; blasts 5% to 20%, 67.4%; blasts > 20%, 75.0%; p=0.342). Donor sources have also no significant effects on DFS (identical sibling 75.6%, unrelated donor 79.2%, haploidentical family member 69.8%; p=0.651).

Conclusions
Our clinical results have shown that under current protocol, DFS of MDS after allogeneic HSCT is quite encouraging no matter the disease status and stem cell donor sources. Therefore, it is not necessary that complete remission is achieved by chemotherapy before transplant. Haploidentical family member is an important alternative donor for patients with MDS when matched either identical sibling or unrelated donor is not available.

Disclosures:
No relevant conflicts of interest to declare.