New approaches needed for children with standard-risk acute lymphoblastic leukaemia

The duration of remission is the most important factor in predicting outcome in children with standard-risk acute lymphoblastic leukaemia, according to a study from the Children's Cancer Group. Children with standard-risk acute lymphoblastic leukaemia (SR-ALL) have a white cell count of less than 50,000/µL, and aged between 1 and 9 years. Event-free survival of this group is more than 80%, but they have a poor prognosis after relapse especially if it is early bone marrow (BM) or isolated extramedullary (EM) relapse. This study analysed outcomes for 347 patients of 2174 enrolled in the Children's Cancer Group CCG-1952 study, who had a relapse after complete remission by day 28 of induction therapy. The overall estimated 3-year overall event free survival (EFS) for all 2027 randomised patients was 81.6% (SD, 1.3%) and overall survival was 92.3% (SD 0.9%). A total of 42.9% of these had isolated BM relapses and 19.6% had combined BM and EM relapses. Results showed that the time to isolated central nervous system relapse was 23 ± 1 months (range, 1 to 88 months), to BM relapse was 36 ± 1 months (range, 2 to 79 months), and to isolated testicular relapse was 40 ± 2 months (range, 16 to 64 months). The overall estimated 3-year EFS2 after BM relapse was 37% ± SE 4% and overall survival was 45.6% ± SE 4.1.1%. Rates after isolated EM relapse were 57% ± SE 5.3% and 71.4% ± SE 4.8%, respectively. Multivariate analysis showed that the only significant predictor of EFS2 after relapse was the duration of first remission. The authors found no significant advantage in using stem cell transplant or chemotherapy for any site of relapse or the length of the first remission. They concluded that the duration of first remission was the most significant predictor of outcome. They noted that prognosis after early BM relapse was poor, was not improved with SCT, and that new approaches are critically needed. Reference...