[The application of a new prognostic score system for 435 cases of primary myelodysplastic syndrome diagnosed with WHO classification].

Objective: To investigate the prognostic factors of myelodysplastic syndrome (MDS) in cases diagnosed with WHO classification and evaluate the validity of International Prognostic Scoring System (IPSS) and WHO Classification-Based Prognostic Scoring System (WPSS) so as to establish a new score system for Chinese MDS patients.
Methods: Four hundred and thirty-five patients diagnosed as primary MDS in Sino-US Leukemia Cooperative Group of Shanghai were studied prospectively to identify the prognostic factors by Log-rank test and Cox regression model.
Results: The 3-year survival rate of MDS was 46.7%. The median survival time of refractory cytopenia with multilineage dysplasia (RCMD) subtype was 38 months and that of refractory anemia with excess blasts (RAEB) subtype was 10 months. Four hundred and twenty-four patients have successful karyotyping. According to the IPSS score, low risk, intermediate risk- I, intermediate risk-II and high risk group accounted for 38/424 (9.0%), 282/424 (66.5%), 74/ 424 (17.5%) and 30/424 (7.1%). Multivariate analysis of Cox model showed old age, lower neutrophil absolute count (NAC), lower hemoglobin, lower platelet count and IPSS group were independent factors associated with overall survival time (OS). WPSS was not an independent prognostic factor. For cases with RCMD, platelet count, IPSS score, IPSS cytogenetics group and chromosome abnormality were not independent prognostic factors; whereas age (> or = 60 years old), NAC (< 1.0 x 10(9)/L), Hb (< 90 g/L) and degree of cytopenia were independent factors. A new score system was established based on these factors. It had better ability to predict OS for RCMD patients as it was proved by univariate and multivariate analysis.
Conclusion: The survival rate and median survival time of MDS in Chinese are similar to those in Western. IPSS score can predict prognosis for all MDS patients and it is better than WPSS. However, both of them have no validity for the prognostication of RCMD subtype. A new score system which can distinguish the different prognoses for RCMD patients is suggested.