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Published on: October 17, 2025
Absolute Lymphocyte Count (ALC) after Induction Treatment Predicts Survival of Pediatric Patients with Acute
Tamas Farkas1, Judit Müller1, Daniel J Erdelyi1
1Semmelweis University, Budapest, Hungary.
Insights
Absolute Lymphocyte Count (ALC) on day 33 of induction chemotherapy is a strong predictor of survival in pediatric Acute Lymphoblastic Leukemia (ALL). Higher ALC levels are linked to better Overall Survival (OS) and Event-Free Survival (EFS).
Area of Science:
- Pediatric Oncology
- Hematology
- Immunology
Background:
- Absolute Lymphocyte Count (ALC) is a newly recognized prognostic factor in pediatric Acute Lymphoblastic Leukemia (ALL).
- Early assessment of prognostic markers is crucial for tailoring treatment strategies in ALL.
Purpose of the Study:
- To evaluate the association between ALC values and survival outcomes (Overall Survival and Event-Free Survival) in pediatric ALL patients during induction chemotherapy.
- To determine the optimal time point for ALC measurement to predict survival in pediatric ALL.
Main Methods:
- Retrospective analysis of 132 pediatric ALL patients treated with the BFM-ALLIC 2002 protocol.
- Kaplan-Meier and Cox regression analyses were used to assess the correlation between ALC levels at various time points and survival outcomes.
- Multivariate analysis was performed adjusting for established prognostic factors.
Main Results:
- An Absolute Lymphocyte Count (ALC) above 350 cells/μL on day 33 of induction chemotherapy was significantly associated with improved Overall Survival (OS) and Event-Free Survival (EFS) (p < 0.001).
- No significant association was found between survival and ALC values measured on earlier days of induction (diagnosis, day 8, day 15).
- Day 33 ALC values refined prognostic information within the flow cytometry Minimal Residual Disease (MRD)-negative cohort, identifying patients with better survival.
Conclusions:
- Absolute Lymphocyte Count (ALC) on day 33 of induction chemotherapy is a robust and independent predictor of survival in pediatric ALL.
- This easily accessible marker can aid in risk stratification and treatment decisions for children with ALL.
- Incorporating day 33 ALC into prognostic models may enhance the accuracy of survival predictions in pediatric ALL.
Abstract:
Absolute Lymphocyte Count (ALC) has been recently established as a prognostic factor of survival in pediatric Acute Lymphoblastic Leukemia (ALL). A retrospective analysis of 132 patients treated according the BFM - ALLIC 2002 protocol was performed in a single institution. A possible association between ALC values and Overall Survival (OS) or Event-Free Survival (EFS) was evaluated at multiple time points during induction chemotherapy. ALC higher than 350 cells/μL measured on the 33th day of induction was associated with better Overall- and Event-Free Survival in both Kaplan-Meier (OS 88.6% vs. 40%; p < 0.001 / EFS 81.6% vs. 30%; p < 0.001) and Cox regression (OS HR 8.77 (3.31-23.28); p < 0.001) and EFS HR 6.61 (2.79-15.63); p < 0.001) analyses. There was no association between survival and measured ALC values from earlier time points (day of diagnosis, days 8 and 15) of induction therapy. Patients with low ALC values tend to have higher risk (MR or HR groups) and a higher age at diagnosis (>10 years). With help of day 33 ALC values of 350 cells/μL cutoff it was possible to refine day 33 flow cytometry (FC) Minimal Residual Disease (MRD) results within the negative cohort: higher ALC values were significantly associated with better survival. ALC on day 33 (350 cells/μL) remained prognostic for OS and EFS in multivariate analysis after adjusting it for age, cytogenetics, immunophenotype and FC MRD of induction day 33. According to these findings ALC on day 33 of induction is a strong predictor of survival in pediatric ALL.
