[Therapeutic Outcomes of 28 ALL Patients with MLL Gene Rearrangement]

Area of Science:

• Pediatric Hematology Oncology
• Molecular Genetics in Leukemia
• Clinical Trial Analysis

Background:

• Acute lymphoblastic leukemia (ALL) in children can have varied prognoses.
• MLL gene rearrangements are a known genetic alteration in ALL, particularly in infants.
• Understanding the impact of MLL rearrangements on treatment outcomes is crucial for optimizing pediatric ALL care.

Purpose of the Study:

• To evaluate the therapeutic outcomes of pediatric ALL patients with MLL gene rearrangement.
• To identify prognostic factors influencing survival in this specific ALL subgroup.
• To assess the effectiveness of the CCLG-ALL 2008 protocol in MLL-rearranged ALL.

Main Methods:

• Retrospective analysis of 28 pediatric ALL patients (<12 years) with MLL gene rearrangement.
• Patients were treated under the CCLG-ALL 2008 protocol from January 2008 to April 2015.
• Outcomes including overall survival (OS) and event-free survival (EFS) were analyzed, with subgroup comparisons based on initial white blood cell (WBC) count.

Main Results:

• The 5-year OS and EFS for 23 evaluable patients were 52.2% and 47.8%, respectively.
• Patients with initial WBC ≥50×10^9/L had significantly lower 5-year OS (28.6%) and EFS (77.8%) compared to those with WBC <50×10^9/L (P=0.048).
• While trends suggested poorer outcomes for infants, good prednisone response, and CD10 negativity, these did not reach statistical significance (P>0.05).

Conclusions:

• Pediatric ALL patients with MLL gene rearrangement treated with the CCLG-ALL 2008 protocol have a 5-year OS of 52.2% and EFS of 47.8%.
• An initial WBC count of ≥50×10^9/L is identified as a significant adverse prognostic factor.
• Further research may refine risk stratification and treatment strategies for this high-risk ALL subgroup.