Cytogenetics and comorbidity predict outcomes in older myelodysplastic syndrome patients after allogeneic stem cell transplantation using reduced intensity conditioning

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment with a curative potential for myelodysplastic syndrome (MDS) patients. Allo-HSCT has substantial risks, particularly in the elderly, and its role for older MDS patients has yet to be defined. METHODS: We analyzed 88 MDS patients aged ≥ 60 years with allo-HSCT after reduced intensity conditioning regimens over the last decade. The study cohort had high risk features; 47 of 88 (53.4%) patients were > 65 years of age, 24 (27%) patients had cytogenetic abnormalities consistent with monosomal karyotype (MKpos), 33 (38%) patients had histological subtype of RAEB-1 and RAEB-2 at diagnosis, and 45 (51%) patients had a hematopoietic cell transplantation–comorbidity index (HCT-CI) of ≥ 3. RESULTS: The 3-year incidence of progression, transplant-related mortality (TRM), and overall survival (OS) were 26% (95% confidence interval [CI], 18%-37%), 35% (95% CI, 26%-47%), and 41% (95% CI, 30%-52%), respectively. MKpos was the only prognostic factor that increased the risk of disease progression compared with good-risk cytogenetics (hazard ratio [HR] = 9.5, P =.003) as well as MKneg (HR = 3.3, P =.01). For TRM, HCT-CI ≥ 3, but not age >65 years, was associated with worse outcomes (HR = 3.1, P =.007). Cytogenetics and HCT-CI enabled us to identify prognostic groups for OS. MKpos patients had the worst 3-year OS (17%), whereas patients with good-risk cytogenetics and HCT-CI < 3 had the best OS (92%). CONCLUSION: Our results confirm that allo-HSCT can provide long-term survival in older MDS patients. Cytogenetics and HCT-CI identify prognostic risk groups and guide selection of older MDS patients who are candidates for allo-HSCT. Cancer 2017;123:2661-70.