Outcome and Risk Factors for Therapy-Related Myeloid Neoplasms Treated with Allogeneic Stem Cell Transplantation

Abstract

BackgroundTherapy-related myeloid neoplasms (t-MN) have a poor prognosis with conventional chemotherapy and a median survival of ≤1 year. Allogeneic stem cell transplantation (HCT) is considered the only effective treatment. EBMT and CIBMTR analyzed their registry data on HCT against t-MN and reported its outcome and developed scoring systems using identified risk factors in HCT. This study aimed to investigate outcome and risk factors in adult patients with t-MN who underwent HCT in Japan.MethodsData sourceFor this retrospective observational study, recipients' clinical data were provided by the Transplant Registry Unified Management Program of Japan society for Hematopoietic Cell Transplantation.DefinitionTherapy-related myeloid neoplasms include therapy-related AML (t-AML), t-MDS, and t-MDS/MPN occurring as late complications of cytotoxic chemotherapy and/or radiation therapy administered for a prior neoplastic or non-neoplastic disorder. Cases with past history of MDS or MPN were excluded because it was not possible to clearly distinguish their neoplasms from an original myeloid neoplasm or therapy-related neoplasm.The primary outcome of the analysis was overall survival (OS), whereas the secondary endpoints included incidence of relapse and transplantation-related mortality (TRM).Cytogenetic risk groups in AML were classified according to the MRC (2010). In MDS, three risk groups were defined using the revised International Scoring System: favorable (very good and good), intermediate (intermediate), poor (poor and very poor). HLA mismatch was defined as incompatibility between the recipient and donor when at least a single allele mismatch was detected at HLA-A, -B, and -DR in related and unrelated donors. In cord blood, HLA mismatch was defined as at least two antigen mismatches detected at HLA-A, -B, and -DR.Statistical analysisOS was estimated using the Kaplan-Meier method and was compared using the log-rank test. Cox's proportional-hazards regression model was used for multivariate analysis of prognostic factors. Cumulative incidence curves were used in a competing-risk setting to calculate the probability of relapse and TRM. Relapse and therapy-related deaths were considered a competing risk event for each other and were compared using Gray's test.ResultsBetween 1992 and 2012, 641 adult patients who had undergone HCTs for confirmed t-MN (not de novo myeloid neoplasms) were identified. Median age at HCT was 53 (range; 16-80) years, with a female proportion of 49%. In total, 414 (64.6%) patients had AML, 215 (33.5%) had MDS, and 12 (1.9%) had MPN. Approximately 50% of patients had a prior history of lymphoma, 14.6% had acute leukemia, and 13.3% had breast cancer. Karyotype was available in 310 cases. Favorable karyotypes were detected in 11 (3.5%) cases, whereas intermediate and poor karyotypes were detected in 122 (39.4%) and in 177 (57.1%) cases, respectively. HLA mismatched HCT was 25.7%. Bone marrow or peripheral HCT from related donors was used in 189 (28.7%) cases, whereas bone marrow HCT from unrelated donor was used in 228 (35.7%) cases, and cord blood HCT was used in 229 (35.6%) cases. Approximately 30% of patients were in remission at HCT.Overall survival was 45.3% [95% confident interval (CI) 45-48], 33% (CI 29-37), and 28% (CI 24-32) at 1, 3, and 5 years, respectively. In multivariate analysis, the significant factors for poor survival were ECOG Performance Status (PS) 2-4 (HR 1.99; CI 1.45-2.72), disease status of non-remission at the time of HCT (HR 1.82; CI 1.33-2.50), patient age of >55 years (HR 1.72; CI 1.32-2.24), and poor karyotype (HR 1.54; CI 1.15-2.05).The cumulative incidence of non-relapse mortality and relapse at 3 years was 37% and 36%, respectively. In a multivariate analysis, the significant factor for non-relapse mortality was patient age of >55 years (HR 1.48; CI 1.09-2.02). For relapse, poor karyotype (HR 2.29; CI 1.65-3.18) was a significant factor.ConclusionsPS 2-4, non-remission, higher patient age, and poor cytogenetics were predictive of poor survival. The outcome of HCT against therapy-related myeloid neoplasms in Japan was comparable to those of EBMT and CIBMTR. DisclosuresUsuki:Novartis: Other: personal fees, Research Funding; GlaxoSmithKline: Other: personal fees, Research Funding; Taiho Pharmaceutical: Other: personal fees, Research Funding; Fuji Film RI Pharma: Other: personal fees; Chugai Pharmaceutical: Other: personal fees; Sumitomo Dainippon Pharma: Other: personal fees, Research Funding; Celgene: Other: personal fees, Research Funding; Boehringer Ingelheim: Other: personal fees, Research Funding; Nippon Shinyaku: Other: personal fees, Research Funding; Shionogi: Other: personal fees; Sanofi: Other: personal fees, Research Funding; MSD: Other: personal fees, Research Funding; SymBio Pharmaceutical: Other: personal fees, Research Funding; Eisai: Research Funding; Otsuka Pharmaceutical: Research Funding; Kyowa Hakko Kirin: Other: personal fees, Research Funding; Shire: Research Funding; Takeda Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Research Funding; Bristol-Myers Squibb: Other; Astellas: Research Funding. Miyazaki:Chugai: Honoraria, Research Funding; Sumitomo Dainippon: Honoraria; Celgene Japan: Honoraria; Kyowa-Kirin: Honoraria, Research Funding; Shin-bio: Honoraria.