Therapeutic results and prognostic predictors of childhood acute lymphoblastic leukemia: Cox regression analysis

Determining the current status of therapeutic results of acute lymphoblastic leukemia (ALL), and identifying the important clinical predictors of survival and relapse are essential for establishing therapeutic strategies. Sixty-two children with ALL who were admitted to Chonnam University Hospital from January 1983 to June 1991 were studied. With a mean follow-up period of 53.7 months, the overall 5-year survival rate (5YSR) was 46.1%. The overall rate of 5-year event-free survival (EFS) was 25.4% and significantly differed between risk groups: 48.7% for standard, 16.3% for high, and 12.5% for very high (p < .05). Overall 4-year survival after initial relapse was 34.2% and there was no significant difference in survival between those who relapsed during maintenance therapy and those who relapsed after completing maintenance. The Cox proportional hazards model identified central nervous system (CNS) irradiation (P < 0.001) as having the most important influence upon EFS, followed by serum alanine aminotransferase level, platelet level, and age. On the other hand, CNS leukemia at diagnosis, followed by mediastinal mass, and hemoglobin level were found to be the most important prognostic predictors for relapse. On the basis that present results differ from those of developed countries, we suggest the necessity of a nation-wide cohort study to delineate the characteristics of Korean ALL in children, to make our own protocols, and ultimately to improve the therapeutic outcome.