Validation of the Revised International Prognostic Scoring System for patients with myelodysplastic syndromes.

The objective of this study is to externally validate the recently published Revised International Prognostic Scoring System (IPSS-R) for myelodysplastic syndrome (MDS) and compare it with the International Prognostic Scoring System (IPSS). We conducted a retrospective study of 173 adult MDS patients who had not received disease-altering treatment. Using the Cox hazard method, we found the IPSS-R to be a significant predictor of survival (p < 0.001, hazard ratio, HR = 1.82, 95% confidence interval, CI 1.57-2.12) and time to acute myeloid leukemia (AML; p < 0.001, HR = 2.05, 95% CI 1.55-2.70). The IPSS-R has greater prognostic power for survival and time to AML compared with the IPSS, given higher Somers' D values (0.41 vs. 0.39 and 0.55 vs. 0.53, respectively). Using the log-rank test, we found a significant difference when comparing IPSS-R groups (p < 0.02), with the exception of the high-risk versus very high-risk group comparison. The IPSS-R reclassified low-risk and intermediate-1 IPSS groups into four groups (log-rank, p < 0.001) and intermediate-2 and high-risk IPSS groups into three groups (log-rank, p < 0.04, excluding high-risk vs. very high-risk comparison). We conclude that the IPSS-R has significant prognostic utility for MDS patients.