Monosomal karyotype predicts poor survival after allogeneic stem cell transplantation in chromosome 7 abnormal myelodysplastic syndrome and secondary acute myeloid leukemia.

Treatment algorithms for poor cytogenetic-risk myelodysplastic syndrome (MDS), defined by chromosome 7 abnormalities or complex karyotype (CK), include allogeneic stem cell transplantation (alloSCT). We studied outcome of alloSCT in chromosome 7 abnormal MDS patients as this data are scarce in literature. We specifically focused on the impact of the extra presence of CK and monosomal karyotype (MK). The European Group for Blood and Marrow Transplantation database contained data on 277 adult MDS patients with a chromosome 7 abnormality treated with alloSCT. Median age at alloSCT was 45 years. Median follow-up of patients alive was 5 years. Five-year progression-free survival (PFS) and overall survival (OS) were 22% and 28%, respectively. In multivariate analysis, statistically significant predictors for worse PFS were higher MDS stages treated, but not in complete remission (CR) (hazards ratio (HR) 1.7), and the presence of CK (HR 1.5) or MK (HR 1.8). Negative predictive factors for OS were higher MDS stages treated, but not in CR (HR 1.8), and the presence of CK (HR 1.6) or MK (HR 1.7). By means of the cross-validated log partial likelihood, MK showed to have a better predictive value than CK. The results are relevant when considering alloSCT for higher-stage MDS patients having MK including a chromosome 7 abnormality.