[Clinical analysis of 7 cases of childhood acute lymphoblastic leukemia with PDGFRB rearrangement].

OBJECTIVES

To investigate the clinical characteristics and prognosis of childhood acute lymphoblastic leukemia (ALL) with PDGFRB rearrangement.

METHODS

A retrospective analysis was conducted of 7 childhood ALL patients with PDGFRB rearrangement who were diagnosed and initiated on therapy at the Children's Hospital, The First Affiliated Hospital of Zhengzhou University from January 2020 to December 2024, assessing clinical features, laboratory findings, treatment, and survival.

RESULTS

Seven children with PDGFRB-rearranged ALL were identified, accounting for 1.0% (7/673) of ALL cases during the same period. There were 3 males and 4 females, with a median age at diagnosis of 8 years (range: 1-12 years). One case was T-acute lymphoblastic leukemia (T-ALL) and 6 cases were B-acute lymphoblastic leukemia (B-ALL). Fusion partners included EBF1-PDGFRB in 4 cases, ROCK1-PDGFRB in 1 case, CCDC88C-PDGFRB in 1 case, and SSBP2-PDGFRB in 1 case. Six patients had concurrent gene mutations, including IKZF1, EBF1, PAX5, CDKN2A, and CDKN2B. One patient was positive for the ETV6-RUNX1 fusion gene, and one for the STIL-TAL1 fusion gene. All 7 patients had normal karyotypes. All patients received chemotherapy, achieving a 100% complete remission rate after one course. Minimal residual disease (MRD) negativity rate was 57% (4/7), and PDGFRB fusion transcript became negative in 3/7 (43%). Three patients underwent allogeneic hematopoietic stem cell transplantation in remission and remain disease-free, while 2 of the 4 non-transplanted patients died.

CONCLUSIONS

PDGFRB-rearranged ALL in children is uncommon, is most often detected in B-ALL, and presents at a relatively older age. Fusion partners are diverse and frequently co-occur with additional gene mutations. Despite high initial remission, MRD negativity and molecular clearance rates remain suboptimal, and allogeneic hematopoietic stem cell transplantation may improve prognosis.