Experts Streamline, Reconcile the 2022 ICC, WHO MDS Classification Systems

An expert panel has reviewed the 2022 International Consensus Classification (ICC) and World Health Organization (WHO) classification systems for myelodysplastic syndromes (MDS) and constructed a common system to classify disease focused on genomic features. The panel presented this system in a consensus paper published in The Lancet Haematology.

“Our data-driven approach can efficiently harmonise current classifications of myelodysplastic syndromes and provide a reference for patient management in a real-world setting,” wrote Rami Komrokji, MBBS, of the H Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, and coauthors.

The expert panel was formed of members of the International Consortium for Myelodysplastic Syndromes. Through a modified Delphi consensus process, the panel assessed the degree to which disease genomic features determined cluster assignments within the ICC and WHO classification systems.

“Morphologically defined myelodysplastic syndrome entities showed large genomic heterogeneity that was not efficiently captured by single-lineage versus multilineage dysplasia, marrow blasts, hypocellularity, or fibrosis,” wrote Dr. Komrokji.

From the two systems’ morphologically-defined disease categories which did not feature distinct genomic profiles, the panel identified nine clusters with distinct genomic features. It found the three clusters of highest hierarchical importance were MDS associated with biallelic TP53 inactivation, MDS with chromosome 5q deletion, and MDS with mutated SF3B1.

Following their review, the panel recognized MDS with blasts of less than 5% and MDS with blasts of 5% or higher as two distinct disease entities.

Reference

Komrokji RS, Lanino L, Ball S, et al. Data-driven, harmonised classification system for myelodysplastic syndromes: a consensus paper from the International Consortium for Myelodysplastic Syndromes [published correction appears in Lancet Haematol. 2024 Oct 30:S2352-3026(24)00339-9. doi: 10.1016/S2352-3026(24)00339-9]. Lancet Haematol. 2024;11(11):e862-e872. doi:10.1016/S2352-3026(24)00251-5