Study Defines Cutoff to Stratify Patients with Intermediate Risk According to IPSS-R

The Revised International Prognostic Scoring System (IPSS-R) is a useful tool to predict clinical outcomes in patients with myelodysplastic syndromes (MDS), and it often guides clinicians and patients when they make treatment decisions.

The IPSS-R stratifies patients with MDS into five risk groups: very low, low, intermediate, high, and very high. A group of researchers from Spain said that because treatment decisions are often based on whether patients are low risk or high risk, they wanted more clarity regarding cutoffs and treatment decisions in the intermediate-risk group.

They conducted a study to determine the specific point on the IPSS-R that best divides patients into low versus high risk, as well as explore clinical characteristics and outcomes in patients labeled as intermediate risk.

The study included all patients diagnosed with MDS between 1980 and 2019 who were in the Spanish Registry of Myelodysplastic Syndromes with all of the variables needed to be classified according to the IPSS-R. The total sample was 4,103.

The researchers calculated prognostic risk according to the IPSS-R, and they defined low risk as those who ultimately had overall survival (OS) of 30 months or more.

Median follow-up for patients who survived was 52.7 months, and median OS was 52.9 months. The researchers found that the IPSS-R cutoff that best identified low-risk disease was 3.5 or lower. This was defined as 75% accuracy predicting OS of 30 months or longer. In the current sample, that equated 2,830 patients (69%) with low-risk disease and 1,273 (31%) with high-risk disease, with median OS rates of 75 months and 15.4 months, respectively.

With the cutoff set at 3.5, most of the patients in this sample who would have been classified as intermediate risk were upgraded to high risk (n=457/706; 65%). In this study, the intermediate-risk group had clinical outcomes that were more similar to patients with high-risk MDS than low-risk MDS, such as lower OS and more risk of transformation into acute myeloid leukemia.

“By using this cutoff, most patients with intermediate-risk MDS according to the IPSS-R are indeed considered as higher risk,” said lead presenter Maria Julia Montoro, MD, PhD, of the Department of Hematology at Vall d’Hebron Hospital Universitari in Barcelona, Spain. “These findings have relevant clinical implications, as they imply that intermediate-risk patients should be managed as high-risk MDS.”