This is an analysis of 516 patients with relapsed ALL report based on the cohort of the Nordic Society of Paediatric Haematology and Oncology (NOPHO) treated with the ALL-92 and ALL-2000 protocols, with total of 516 patients with relapsed ALL. Statistically significant adverse prognostic factors included shorter time to relapse (worse if earlier), site of relapse (worse ifbone marrow involvement at relapse involving the bone marrow), age ten years or over at primary diagnosis, unfavorable cytogenetics, Down syndrome, and T-cell lineage with hyperleukocytosis at primary diagnosis. In the whole study population of relapsed ALL patients, the 5-year EFS was 43.7±2.3% and the 5-year OS was 51.5±2.3%. Further subgroup analysis based on time period, risk groups, relapse treatment protocols and HSCT are reported. Analysis of prognostic factors, validation of the current risk stratification and comparison of treatment modalities could be helpful in improving treatment for relapsed childhood ALL.
* Outcomes of relapse ALL in a large population based cohort with long follow up period is presented in this paperOS of this large cohort of relapsed pediatric ALL patients treated on the NOPHO ALL-92 and ALL-2000 was about 50% with confirmation of known adverse risk factors such as older age at diagnosis, unfavorable cytogenetics, T-cell lineage with hyperleukocytosis, Down syndrome, shorter time to relapse, and bone marrow involvement at relapse.