Superior treatment results in females with high-risk acute lymphoblastic leukemia in childhood.

In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norway and Sweden, were diagnosed between July 1981 and June 1986 as suffering from non-B-cell acute lymphoblastic leukemia (ALL). The total population was 4.5 million children. Remission was achieved in 770/808 of the patients (95%). No sex difference in the remission rate was observed. The event free survival (EFS) at 102 months was 0.47 for males and 0.62 for females (p less than 0.001). There was no difference in EFS between males and females with standard-risk (0.58 and 0.60) or intermediate-risk (0.47 and 0.60) ALL, respectively. The EFS for females with high-risk ALL (0.68) was superior to that of males with high-risk ALL (0.31). Cox multivariant analysis showed that white blood cell count, sex, age and thrombocyte count were significant prognostic factors in all children. The intensified treatment according to the prognostic factors used in this study led to equal EFS for females with ALL from all risk groups. Males with high-risk ALL, however, did not benefit from the intensified treatment.