Long term outcomes for children with acute lymphoblastic leukemia treated with the SCMC-ALL-2009 protocol

This study aimed to investigate the long-term treatment outcomes and prognostic factors of acute lymphoblastic leukemia (ALL) in pediatric patients who took part in the SCMC-ALL-2009 trials.  

This study concluded that the long-term outcomes were favorable for these patients and better for low-risk patients when compared to high-risk patients.  

Acute lymphoblastic leukemia (ALL) is rare but it is the most common type of leukemia that affects children. Treatment protocols for ALL are continually changing in order to improve patient outcomes. A previous trial investigated the outcomes of children with ALL treated according to the SCMC-ALL-2005 protocol. This protocol was revised and improved as the SCMC-ALL-2009 protocol.

The SCMC-ALL-2009 protocol consisted of induction (first treatment) with VDLP (vincristine, daunorubicin, L-asparaginase, and prednisolone), consolidation (kills any cancer cells left after first treatment), central preventive (treatment that prevents leukemia spread to the brain), re-induction, and maintenance therapy (prevents cancer returning). In this protocol, patients were put in different risk categories and treatment doses were adapted according to risk category.

Compared to the 2005 protocol, the 2009 protocol increased the doses of daunorubicin, anthracyclines, and L-asparaginase for children in the intermediate-risk group and the prednisolone dose in the low-risk group. No changes were made for high-risk patients. The long-term treatment outcomes and prognostic factors were for the patients treated according to the SCMC-ALL-2009 protocol are unknown.  

This study involved 100 pediatric patients, aged under 2 years who were involved in the SCMC-ALL-2009 study. Patients were followed up for an average of 62 months. 

The 5-year event-free survival (EFS; survival without complications from ALL) was 74.7%. The 10-year EFS was 73.3%. The 10-year EFS rate for low-risk patients was 81.9% compared to 71.3% for intermediate-risk patients and 22.2% for high-risk patients.  

The overall survival (OS) at 5 and 10 years was 79.2% for all patients. 10-year OS was 95.1% for low-risk patients, 78.8% for intermediate-risk patients, and 22.2% for high-risk patients.  

Relapse occurred in 19 patients. Factors that had impacted outcomes were minimal residual disease (MRD; a small number of leukemia cells left after induction treatment) results on day 55, good or poor response to prednisolone, and age at diagnosis. 

Compared to the SCMC-ALL-2005 protocol, 10-years EFS improved in low-risk patients (from 75.1% to 84.9%) and in intermediate-risk patients (from 56.2% to 71.3%). 

This study concluded that the long-term outcomes were favorable for ALL pediatric patients who took part in SCMC-ALL-2009 trials and outcomes were better for low-risk patients when compared to high-risk patients. 

This study only included Chinese children. Therefore, the results may not apply to all populations.