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Updated: Aug 30, 2026
Murine Model of Leukemia Relapse to Induction Chemotherapy for Acute Lymphoblastic Leukemia
Published on: October 17, 2025
Long-term follow-up of relapsed childhood acute lymphoblastic leukaemia
Judith M Chessells1, Paul Veys, Helena Kempski
1Department of Haematology/Oncology, Great Ormond Street Hospital, London, UK.
Insights
Relapse in childhood acute lymphoblastic leukemia (ALL) often occurs within 3 years. The German relapse score effectively predicts outcomes, but new strategies are needed for high-risk patients and those in third remission.
Area of Science:
- Pediatric Oncology
- Hematology
Background:
- Acute lymphoblastic leukemia (ALL) is the most common childhood cancer.
- Relapse remains a significant challenge in pediatric ALL treatment.
- Understanding outcomes after relapse is crucial for improving survival rates.
Purpose of the Study:
- To analyze the outcomes of children with relapsed acute lymphoblastic leukemia (ALL).
- To identify factors influencing survival after relapse.
- To evaluate the predictive power of the German relapse score and compare treatment modalities.
Main Methods:
- Retrospective review of 505 children with relapsed ALL.
- Analysis of relapse timing, site, and patient characteristics.
- Application of the German relapse score and comparison of intensive chemotherapy versus bone marrow transplantation (BMT).
Main Results:
- Most relapses (74%) occurred within 3 years, often involving bone marrow.
- Early relapse was associated with T-ALL and unfavorable cytogenetics.
- The German relapse score accurately predicted event-free survival, with 6-year rates of 78% (standard risk), 41% (intermediate risk), and 19% (highest risk).
- BMT showed a potential advantage over chemotherapy in the highest-risk group.
Conclusions:
- The German relapse score is a strong predictor of outcome in pediatric ALL relapse.
- Current treatment strategies require refinement for intermediate and highest-risk groups.
- Novel therapeutic approaches are necessary to improve survival in relapsed pediatric ALL, especially for patients requiring third-line treatment.
Abstract:
We have reviewed the outcome after relapse in a cohort of 505 children with acute lymphoblastic leukaemia (ALL) seen at a single institution. The majority of relapses (74%) occurred within 3 years from diagnosis, and most involved the bone marrow alone or with overt extramedullary relapse. Early relapse was more common in children with T-ALL and those with unfavourable cytogenetics. Factors influencing second remission included length of first remission and type of relapse. Children who had not received previous cranial irradiation had a superior survival. The German relapse score involving length of first remission, site of relapse and immunophenotype was highly predictive of outcome: event-free survival with 95% confidence intervals at 6 years for patients who received modern treatment [intensive chemotherapy or bone marrow transplantation (BMT)] was 78% (51-92%) for standard risk, 41% (33-49%) for intermediate risk and 19% (10-31%) for highest risk. Retrospective comparison of BMT with chemotherapy showed no difference in the intermediate-risk group but a possible advantage in the highest risk group. Follow-up of 235 patients who relapsed after chemotherapy and received a third course of treatment showed an extremely high early attrition rate, but a small number of patients survived in third remission. We conclude that new approaches are needed to individualize therapy in intermediate-risk patients and to improve the outcome for those in the highest risk group. Only a small number of children can be treated effectively in third remission.
