Outcome and prognostic factors of acute lymphoblastic leukemia in children at the National Cancer Institute, Egypt.

Objective: To improve survival of children with acute lymphoblastic leukemia (ALL) in the authors' institute and to define significant prognostic factors.

Methods: This study included 154 children with newly diagnosed ALL below the age of 18 years during the period August 1, 1998, to December 31, 2000. All patients were treated according to the NCI, Cairo, Egypt, treatment protocol modified from study XIII for high-risk ALL of St. Jude Children's Research Hospital.

Results: B-cell precursor phenotype was encountered in 73.4% of patients, T-cell in 26.6%. According to NCI/Rome criteria for risk classification, 58.4% of patients were in the high-risk group (90% of T-lineage compared with 47% of B-lineage ALL, P < 0.001). Nine patients (5.8%) died during induction and 10 patients (6.5%) failed to achieve remission. With a median follow-up of 43 months, the 3-year disease-free survival and its probability at 5 years were 80 +/- 3.6% and 75.3 +/- 4%, respectively; the 3-year event-free survival and its probability at 5 years were 69 +/- 3.8% and 65.2 +/- 4%, respectively. B-cell precursor ALL had 5-year probabilities of disease-free survival and event-free survival of 80.5 +/- 4% and 71.8 +/- 4.5% compared with 60.2 +/- 8.6% and 46.7 +/- 8% for T-cell, respectively (P < 0.01, log-rank test). Prognostic factors that had a statistically significant unfavorable impact on survival by univariate analysis were age 10 years or more, central nervous system involvement, T-lineage phenotype, high-risk group, DNA index less than 1.16, and slow early response to treatment. By multivariate analysis, central nervous system involvement, high-risk group, and slow early response to treatment still had prognostic significance. Risk classification demonstrated prognostic significance for B-lineage but not T-lineage ALL.

Conclusions: This treatment protocol was effective in improving ALL survival among patients at the authors' institute compared with previous trials, although the outcome remains lower than that in more industrialized countries. Prognostic factors defined in this study were similar to those identified by other cooperative groups.