Incidence and prognostic significance of karyotype abnormalities in de novo primary myelodysplastic syndromes: a study on 331 patients from a single institution.

The impact of clinical parameters, International Prognostic Scoring System (IPSS) scores/cytogenetic categories, and some single cytogenetic defects on overall survival (OS) and time to myelodysplastic syndromes (MDS)/AML progression (progression-free interval (PFI)) was evaluated in 331 MDS patients. Statistical analysis demonstrated that OS and PFI were significantly affected by all these parameters. Since single 7q- showed a better survival than the poor IPSS cytogenetic category (P=0.009), it was considered as a new prognostic entity ('modified IPSS categories'). In multivariate analysis OS was significantly influenced by age, marrow blast cell percentage, number of cytopenias and either modified or standard IPSS cytogenetic categories; hazard ratios for MDS/AML progression were influenced by all the former, except for age and cytopenias. Multivariate analysis of del(7)(q31q35) confirmed the results of univariate analysis, but the Akaike Information Criterion showed no difference in evaluating OS and PFI between the modified and standard IPSS cytogenetic grouping. In conclusion, (i) chromosome defects as grouped by IPSS and blast cell percentage are the most relevant parameters for predicting OS and PFI; (ii) the prognostic power of the IPSS cytogenetic grouping is not ameliorated by the introduction of del(7)(q31q35) as a new entity; (iii) complex karyotypes have a prognostic value independent of blast cell percentage. Leukemia (2005) 19, 1424-1431.