OUTCOME AFTER FIRST RELAPSE IN CHILDREN WITH ACUTE LYMPHOBLASTIC-LEUKEMIA - A POPULATION-BASED STUDY OF 315 PATIENTS FROM THE ORDIC-SOCIETY-OF-PEDIATRIC-HEMATOLOGY-AND-ONCOLOGY (NOPHO)

This study reports the outcome after relapse of acute lymphoblastic le ukemia (ALL) in a population-based study of 809 children over 1 year o f age diagnosed July 1981 through June 1986 and with non-B acute lymph oblastic leukemia in the five Nordic countries. By January 1994, 315 c hildren had suffered at least one relapse. The bone marrow was involve d in 216 cases. There were 69 isolated CNS relapses, 25 isolated testi cular recurrences and five relapses in other extramedullary sites. Of the 315 children with relapse, 94 are still in a second complete remis sion 12-138 (median: 78) months after relapse. The overall probability of a second event free survival (P-2.EFS) and survival after relapse was 0.28 and 0.33 respectively. The probability of remaining in second remission at 11 years was significantly correlated to the duration of first remission (P < 0.001), the site of relapse (P < 0.001) and gend er (P = 0.004). The P-2.EFS for early, intermediate, and late bone mar row involved relapses were 0.08, 0.19, and 0.50 respectively. For earl y, intermediate and late isolated CNS relapses the P-2.EFS were 0.21, 0.38 and 0.61, respectively. The P-2.EFS for boys with isolated testic ular relapses was 0.69. Girls with isolated CNS relapse (P < 0.001) an d with bone marrow involved relapse (P = 0.04) had a significantly bet ter prognosis than boys. Children with initial high risk criteria, esp ecially T-ALL and mediastinal mass who relapsed, had a very poor progn osis. Conclusion: In this population-based study, about 30% of childre n with ALL obtained a long second remission and possible cure. (C) 199 5 Wiley-Liss, Inc.