Prognostic value of the revised International Prognostic Scoring System five-group cytogenetic abnormality classification for the outcome prediction of hematopoietic stem cell transplantation in pediatric myelodysplastic syndrome.

Cytogenetic abnormalities are a major risk factor for relapse after hematopoietic stem cell transplantation (HSCT) for myelodysplastic syndrome (MDS). We aimed to evaluate the value of the five-group cytogenetic classification according to the revised International Prognostic Scoring System (R-IPSS) for predicting the outcome after HSCT in pediatric patients with MDS. We retrospectively analyzed the Japanese registration data of 242 pediatric patients with MDS. According to the R-IPSS classification, 112 (45.5%) patients had good, 55 (22.7%) had intermediate, 64 (26.4%) had poor, and 11 (4.6%) had very poor cytogenetics. The 5-year overall survival (5yOS) was 72%, 69%, 59%, and 30% in the good, intermediate, poor, and very poor cytogenetic subgroups (p = 0.026), respectively. The very good, good, and intermediate subgroups were grouped into a "standard" subgroup and reclassified into three subgroups (standard, poor, and very poor). Patients with very poor risk had worse 5yOS (hazard ratio 2.17, 95% confidence interval (CI) 1.02-4.61; p = 0.04) and a much higher 5yCIR (hazard ratio 2.52, 95% CI 1.05-6.04; p = 0.04) than those of patients in the standard group in the multivariate analysis, indicating that very poor risk cytogenetic characteristics independently predicted worse outcome after HSCT in pediatric patients with MDS.