Monosomal karyotype is an independent predictor of survival in patients with higher-risk myelodysplastic syndrome.

A monosomal karyotype (MK) correlates with poor survival in patients with acute myeloid leukemia, although whether this is also the case in patients with myelodysplastic syndrome (MDS) remains controversial. Some studies report a correlation between a MK and a worse survival, whereas others claim that this correlation arises because of a confounding effect between a MK and a complex karyotype (CK). To address this question, we analyzed the clinical data and karyotypes of 610 adults with MDS. A MK was identified in 60 patients, of whom 55 (92%) also fulfilled the criteria for a CK. Conversely, a CK was found in 85 patients, of whom 55 (65%) also had a MK. To determine the impact of a MK on survival, 464 patients who received nonintensive therapies for MDS were analyzed separately. Patients with a MK demonstrated worse survival than those without a MK in univariate analyses (median, 8 months [95% CI, 3-12 months] versus 83 months [63-103 months]; P < 0.001). This effect was observed predominately in the cohorts of higher-risk patients according to the Revised International Prognostic Scoring System and the World Health Organization Prognostic Scoring System (HR [hazard ratio] 3.94 [1.97-7.89]; P < 0.001 and 4.937 [2.45-9.94]; P < 0.001, respectively) and surpassed the impact of a CK in the final survival models. Our data suggest that the addition of MK as a binary variable could improve the predictive accuracy of current models to estimate the survival of patients with MDS.