[Clinical features and prognostic factors of advanced myelodysplastic syndromes in children]

Objective: To investigate the clinical features and prognostic factors of advanced myelodysplastic syndromes (MDS) in children. Methods: Clinical data of children diagnosed with advanced MDS in the Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences, between September 2009 and April 2022 were retrospectively collected. Follow-up assessments were performed through telephone interviews and the review of medical records until May 1, 2023. The clinical features of children with advanced MDS were summarized by analyzing chromosomal karyotype tests, second-generation gene sequencing results. Multivariate Cox regression analysis was used to investigate the prognostic factors of advanced MDS in children. Results: A total of 69 children, comprising 49 males and 20 females, aged [M (Q₁, Q₃)] 8 (5, 10) years, were enrolled in the study. Sixty-seven cases underwent chromosomal karyotype testing, of which 42 cases (62.7%) had abnormal karyotypes, with monosomy 7 the most common in 17 cases (25.4%). Forty-three cases underwent next-generation sequencing, with mutations in the SETBP1, NRAS, PTPN11 and RUNX1 genes more common, identified in 12 cases (27.9%), 9 cases (20.9%), 8 cases(18.6%), and 8 cases(18.6%), respectively. The follow-up time [M (Q₁, Q₃)] was 26 (13, 56) months and the 5-year overall survival rate was 56%(95%CI: 44.4%-70.5%). The 5-year overall survival rate for children who underwent hematopoietic stem cell transplantation (HSCT) was higher than that of children who did not undergo HSCT (73.9% vs 29.1%, P<0.001). HSCT (HR=0.118, 95%CI: 0.037-0.372, P<0.001) was a protective factor for the overall survival rate of children with advanced MDS. Serum ferritin level>356.3 μg/L (HR=6.497, 95%CI: 2.068-20.415, P=0.001) and moderate to severe splenomegaly (HR=4.075, 95%CI: 1.174-14.141, P=0.027) were risk factors for the overall survival rate of children with advanced MDS. Conclusions: Monosomy 7 was the most common abnormal karyotype and SETBP1 was the gene that had the highest mutation frequency in children with advanced MDS. HSCT, increased ferritin and moderate to severe splenomegaly are prognostic factors influencing the overall survival rate of children with advanced MDS.