Chapter 24 Myelodysplastic Syndromes
Biology and Treatment
Table 24-1 French-American-British Classification Criteria*
WHO 2008 classification:
Refractory anemia with unilineage dysplasia
Refractory anemia
Refractory neutropenia
Refractory thrombocytopenia
Refractory anemia with ring sideroblasts
Refractory cytopenia with multilineage dysplasia (with or without ringed sideroblasts)
Refractory anemia with excess of blasts-1
Refractory anemia with excess of blasts-2
Myelodysplastic syndrome, unclassifiable
Myelodysplastic syndrome with deletion 5q
Table 24-2 International Prognostic Scoring System for Myelodysplastic Syndrome
| Overall Score* | Median Survival (Years) | 25% AML Evolution (Years) |
|---|---|---|
| Low (0) | 5.7 | 9.4 |
| Intermediate-1 (0.5-1.0) | 3.5 | 3.3 |
| Intermediate-2 (1.5-2.0) | 1.2 | 1.1 |
| High (≥2.5) | 0.4 | 0.2 |
AML, Acute myelogenous leukemia.
The percent of myeloblasts are scored as follows: <5% = 0; 5%-10% = 0.5: 11%-20% = 1.5: 21%-30% = 2.0.
Cytogenetic features associated with good prognosis are scored as 0 and include normal karyotype, loss of Y, 5q–, or 20q–; those associated with a poor prognosis are scored as 1.0 and include abnormalities of chromosome 7 or three or more cytogenetic changes; all other cytogenetic abnormalities are scored as 0.5 and are of intermediate prognosis.
A score of 0 refers to a patient with either zero or one cell lineage cytopenia, and a score of 0.5 is assigned to two or more lineage cytopenias. Lineage cytopenias are defined as hemoglobin <10 g/dL, absolute neutrophil count <1800/mm3, and platelet count <100,000/mm3.
*The overall score is the sum of the scores from the percent of bone marrow myeloblasts, karyotype, and cytopenias.
Data from Greenberg P, Cox C, LeBeau MM, et al: International scoring system for evaluating prognosis in myelodysplastic syndromes (published erratum appears in Blood 91:1100, 1998). Blood 89:2079, 1997.
Table 24-3 World Health Organization Classifications of MDS
The World Health Organization has reclassified chronic myelomonocytic leukemia (CMML) within the myeloproliferative disorders (MPD) and RAEB-T to “AML with multilineage dysplasia.” Acute myeloid leukemia (AML) is now classified as ≥20% myeloblasts.
The following are considered AML regardless of blast percentage: t(8;21)-AML1/ETO, t(15;17)-PML/RARA, inv(16) or t(16;16)-CBFβMYH11, and 11q23-MLL.
