A Survival Analysis of Pediatric Acute Lymphoblastic Leukemia in Morocco

As a WHO's Global Initiative for Childhood Cancer pilot site, Morocco conducted a study on the overall survival rates of the six WHO index diseases. The objectives of this study were to estimate the survival rates for childhood acute lymphoblastic leukemia (ALL) diagnosed at Moroccan Pediatric Hematology and Oncology (PHO) centers, to identify factors of treatment failure, and to explore opportunities for improvement.

This retrospective study included children with ALL aged 0-15 years. Patients were monitored with active follow-up until March 31, 2023. The Kaplan Meier method was used to estimate survival rates, the log-rank test to compare survival, and the Cox model to identify prognostic factors.

Data included 425 patients; most were aged 1-10years (n=318, 74.9%), and males (n=239, 56.2%). The complete remission induction rate was 84%. One-, three- and five-year overall survival rates were 78.7%, 63.8% and 60.8%, respectively. In a multivariate Cox model regression, age group, phenotype, complete remission following induction and white blood cell count > 50,000/mm3 were statistically associated with survival. Children with T-cell ALL were also more likely to die compared to those with B-cell ALL (HR=2.33 p<0.001).

The 5-year survival rate in our study was 60.8%, below Morocco's 80% target by 2030. Among 203 events, 86 were relapses, 34 resulted from treatment abandonment, and 55 from treatment-related toxicity. While relapse is the leading cause of treatment failure, prioritizing the reduction of treatment abandonment and toxicity-related mortality is a more feasible first step.