Survival trends and cure rates of hematological neoplasms in the Spanish pediatric population.

Hematological neoplasms (HN) were the first cause of death in children aged 5-9 years in Spain. The aim of this registry-based study is to provide a detailed overview of the survival of HN in the Spanish pediatric population. All pediatric HN cases included were classified according to the International Classification for Childhood Cancer. Flexible parametric models were used to estimate survival probabilities and long-term survival projections. Survival trends were evaluated with the annual average change in survival (AAC_S). Latent cure models were used to estimate cure fractions (CF). A total of 4706 cases of HN were diagnosed in Spain during 2000-2016, for which 2850 (60.6%) were boys. Leukemias and lymphoid leukemias (LL) were the most common type and subtype of HN in children. An overall 5- year survival of 84.3% [95% confidence intervals (CI): 83.3, 85.3] was observed for HNs. Children aged < 1 year with acute myeloid leukemia (AML) or myelodysplastic syndrome had the worst prognosis. An improvement over time was observed for all HN with an AAC_S of 0.71% [95% CI 0.50, 0.91], of which AML and Burkitt lymphomas displayed the greatest improvements. HNs revealed CF of 83.8% [95% CI 82.4, 85.3], with the highest CF being nearly 100% in Hodgkin lymphomas. Larger population coverage with updated data have aligned the Spanish results to those observed in other European countries. Continuous refinements in treatments, patient care and better diagnostic methods have revealed the highest survival improvements for HN subtypes with bad prognosis in children.