Comment on: “The impact of category, cytopathology and cytogenetics on development and progression of clonal and malignant myeloid transformation in inherited bone marrow failure syndromes”

摘要

The paper by Cada et al . published in Haematologica uses data from the Canadian Inherited Marrow Failure Registry to examine the prognostic value of the category, cytopathology and cytogenetics (CCC) classification for pediatric myelodysplastic syndrome (MDS).~(~(1)) We have previously expressed some reservations about this classification system, and remain concerned about its utility.~(~(2)) The CCC classification, introduced in 2002, has not been widely employed, while a simpler description of childhood MDS was published more recently by the World Health Organization (WHO) in 2008.~(~(3)) In our opinion, the application of the CCC system to the Canadian Registry introduces more confusion than clarity into our understanding of MDS or leukemia in patients with inherited bone marrow failure syndromes (IBMFS). In addition, the introduction of new abbreviations such as CMMT (clonal and malignant myeloid transformation) and CMCA (clonal marrow cytogenetic abnormalities) make it hard to compare or combine results from the Canadian Registry with other IBMFS registries.We have several specific concerns. First, the paper states a plan to examine the prognostic utility of the three components of the CCC classification. The first component, category, has syndrome as part of the case definition for the Registry, and thus in fact cannot be analyzed. The second component, cytology, includes RC, refractory cytopenia without dysplasia. The supplement to the paper states that patients are enrolled in the Registry if they have chronic bone marrow failure, which appears to be very similar to their definition of RC. Hence this component of the CCC definition also appears difficult to analyze.