IPSS-R in 555 Taiwanese patients with primary MDS: Integration of monosomal karyotype can better risk-stratify the patients.

The revised International Prognostic Scoring System (IPSS-R) was recently developed to better assess the clinical outcome of adult patients with myelodysplastic syndrome (MDS). In this study, we aimed to investigate the prognostic impact of this new risk model on 555 MDS patients in Taiwan. Generally, the IPSS-R could discriminate MDS patients regarding risk of leukemia evolution and overall survival in our cohort and it further refined prognostic stratification in all IPSS risk categories. However, we could not find the inter-group difference between IPSS-R very low and low risk subgroups in both leukemia-free survival (LFS) and overall survival (OS). IPSS-R couldn't distinguish the prognosis between very good and good and between good and intermediate risk cytogenetic categories in OS, and between very good and good and between intermediate and poor cytogenetic-risk categories in LFS, either. On the other hand, incorporation of monosomal karyotype (MK) into IPSS-R could further stratify MDS patients with higher-risk IPSS-R (intermediate, high and very high risk) into four groups, rather than three groups, with different OS (P < 0.001). Intriguingly, patients receiving allogeneic hematopoietic stem cell transplantation had longer survival than those without in the IPSS-R high and very high, but not other risk groups. Similarly, patients treated with hypomethylating agents had better survival than those not in the IPSS-R very high risk group. In conclusion, IPSS-R can risk-stratify MDS patients in Taiwan but with some limitations, especially in very low risk category, and MK has additional prognostic value in discriminating MDS patients with higher-risk IPSS-R.