PEDIATRIC MYELODYSPLASIA - A STUDY OF 68 CHILDREN AND A NEW PROGNOSTIC SCORING SYSTEM

Clinical, morphologic, and cytogenetic features were examined in a gro up of 68 children with myelodysplasia (MDS) referred to a single insti tution between 1971-1991. The morphologic French-American-British (FAB ) system of classification proved of limited value in this group of pa tients because 50% of the cases were categorized as chronic myelomonoc ytic leukemia and three patients with eosinophilia and MDS were unclas sifiable. Cytogenetic analysis was performed in 63 cases and clonal ab normalities were detected in 55%; the most common chromosome involved was number 7. Modification of the FAB system to incorporate additional diagnostic features such as pretreatment fetal hemoglobin (Hb F) and cytogenetics allowed incorporation of the categories of juvenile chron ic myeloid leukemia (JCML) and infantile monosomy 7 syndrome (IMo7). T he resulting groups of patients had highly significant differences in survival (P = .00009). The overall 5-year survival for the patients wa s 31.9% (95% CI 21.7 to 44.1) and factors influencing prognosis includ ed: modified FAB type, platelet count, Hb F level, and cytogenetic com plexity. We developed a scoring system (''FPC'') where each of the fol lowing findings at diagnosis scored one point: HbF greater than 10%, p latelets less than or equal to 40 x 10(9)/L, and complex karyotypic ch anges (two or more clonal structural/numerical abnormalities), which p roduced groups with highly significant differences, patients with a sc ore of 0 having a 5-year survival of 61.6% (CI 33% to 84%), whereas th ose with a score of two or three all died within 4 years of diagnosis. The revised classification and scoring system may prove helpful in ma king treatment choices in pediatric MDS and now needs to be tested pro spectively in large scale population-based studies. (C) 1995 by The Am erican Society of Hematology.