Researchers studied features of myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) in comparison with another condition categorized as MDS/MPN-unclassifiable with ≥15% bone marrow ring sideroblasts (MDS/MPN-U-RS) and found some similarities in key characteristics. The study results were published in Blood Cancer Journal.

According to the researchers, MDS/MPN-RS-T is considered by the World Health Organization to be its own entity within the classification of MDS/MPN. However, the researchers indicated the natural history and clinical and prognostic features of MDS/MPN-RS-T had not been well characterized.

The study was performed by researchers at Mayo Clinic in Rochester, Minnesota, and H. Lee Moffitt Cancer Center in Tampa, Florida. Included patients had either MDS/MPN-RS-T or MDS/MPN-U-RS, and clinical features and outcomes were compared between these 2 conditions.

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There were 158 patients with MDS/MPN-RS-T and 25 patients with MDS/MPN-U-RS included in this analysis. Patients of both groups had a median age of 71 years, and the most recent study follow-up was at a median of 62 months.

SF3B1 mutations appeared to be more common in patients with MDS/MPN-RS-T (92%) than in patients with MDS/MPN-U-RS (40%; P =.003). Multiple other molecular abnormalities appeared to occur at similar rates between the 2 conditions. The acute myeloid leukemia transformation rate was higher in patients with MDS/MPN-RS-T (4%) than with MDS/MPN-U-RS (0%; P =.0003).

Survival outcomes were similar between the 2 conditions. The median overall survival (OS) rates were 6 years with MDS/MPN-RS-T and 7.3 years with MDS/MPN-U-RS (P =.3). The leukemia-free survival rate was not reached for either group (P =.4). Thrombosis events did not occur at significantly different rates between groups (P =.3).

In patients with MDS/MPN-RS-T, univariate analysis revealed certain characteristics that appeared associated with poorer OS. These included an age of 70 years or more (P =.006), an abnormal karyotype (excluding -Y; P =.008), and a hemoglobin level of ≤10 g/dL (P =.03). OS did not appear to be impacted by ASXL1, SF3B1, or JAK2 V617F mutations in patients with MDS/MPN-RS-T.

In multivariate analysis, only an abnormal karyotype (P =.001) and a hemoglobin level of ≤10 g/dL (P =.03) were identified as significant prognostic factors. These 2 factors were used to stratify patients into 3 risk categories. The low-risk category had 0 risk factors and a median OS of 10.5 years, the intermediate-risk category had 1 risk factor and a median OS of 4.8 years, and the high-risk category carried 2 risk factors and a median survival of 1.4 years.

Based on this study’s findings, the researchers suggested that the categories of MDS/MPN-RS-T and MDS/MPN-U-RS could be combined into a category called “MDS/MPN-RS”, pending further research. “In conclusion, the findings from the current study did not identify molecular abnormalities as predictors of survival in MDS/MPN-RS-T, and also argue against the use of currently applied exclusionary criteria in defining MDS/MPN-RS-T, separate from MDS/MPN-U-RS,” the researchers concluded in their report.

Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.


Mangaonkar AA, Lasho TL, Ketterling RP, et al. Myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T): Mayo-Moffitt collaborative study of 158 patients. Blood Cancer J. 2022;12(2):26. doi:10.1038/s41408-022-00622-8