Assessment of Minimal Residual Disease in Childhood Acute Lymphoblastic Leukemia: A Multicenter Study From Turkey

Assestment of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) is of utmost importance both for risk classification and tailoring of the therapy. The data of pediatric ALL patients that received treatment with Berlin-Frankfurt-Munster (BFM) protocols were retrospectively collected from 5 university hospitals in Turkey. Of the 1388 patients enrolled in the study 390 were treated according to MRD-based protocols. MRD assestment was with real time quantitative polymerase chain reaction (qPCR) in 283 patients and with multiparametric flow cytometry (MFC)-MRD in 107 patients. MRD monitoring had upstaged a total of 8 patients (2%) from intermediate risk group to high-risk group. Univariate analysis revealed age 10 years or above, prednisone poor response, PCR-MRD >= 10(-3) on day 33 and on day 78 as poor prognostic factors affecting event-free survival (EFS). Detection of >10% blasts on day 15 with MFC (MFC-high-risk group) was not shown to affect EFS and/or overall survival (log-rank P=0.339). Multiple logistic regression analysis revealed PCR-MRD >= 10(-3) on day 78 as the only poor prognostic factor affecting EFS (odds ratio: 8.03; 95% confidence interval: 2.5-25; P=0.000). It is very important to establish the infrastructure and ensure necessary standardization for both MRD methods for optimal management of children with ALL.

Automated summary

Assessing minimal residual disease (MRD) is crucial for risk classification and personalized therapy in childhood acute lymphoblastic leukemia (ALL). A study in Turkey retrospectively collected data of pediatric ALL patients treated with Berlin-Frankfurt-Munster (BFM) protocols. MRD assessment was done using real-time quantitative polymerase chain reaction (qPCR) and multiparametric flow cytometry (MFC). MRD monitoring led to upgrading 2% of patients from intermediate risk group to high-risk group. Factors such as age ≥10 years, poor response to prednisone, PCR-MRD ≥10(-3) on day 33 and day 78 were identified as poor prognostic factors affecting event-free survival (EFS). Establishing infrastructure and ensuring standardization for MRD methods are crucial for optimal management of children with ALL.