Participating in the study, based on the data of 90,000 children, provided by 198 cancer registers from 53 countries between 2005-2009, was Dr Rafael Marcos-Gragera, epidemiologist of the Catalan Institute of Oncology (ICO) - Oncology Master Plan and researcher at the Biomedical Research Institute of Girona (IDIBGI).
The digital version of the prestigious journal The Lancet Hematology has just published an international study that reflects global inequalities in childhood leukaemia survival rates and highlights the need for better care.
According to the latest data from another study on the global incidence of childhood cancer, published in The Lancet Oncology and in which IDIBGI researchers also participated, leukaemia is the most common cancer among children aged 0 to 14 years worldwide. The authors have also estimated survival for two types of childhood leukaemia: acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML). The study reveals that despite global inequalities in childhood leukaemia survival rates having fallen, there are still considerable international differences. Thus, for example, the five-year survival rate for acute lymphoblastic leukaemia (ALL) in Germany was 92% in comparison with 52% in children diagnosed in Colombia in the same period. Furthermore, it is clear that the survival rate has improved for the majority of age groups but remains low in children aged less than 1 year.
Increase in survival
If age differences and risk of death due to other causes between countries and regions are taken into account, the researchers found that the five-year survival rate for childhood ALL and AML increased in the majority of countries between 1995 and 2009. In general, the survival of children diagnosed with ALL was the highest, with the possibility of surviving at least five years between 11% (China) and 87% (Austria) for children diagnosed between 1995 and 1999. Between 2005-2009 this range was reduced from 52% (Colombia) and 92% (Germany).
In the case of AML, despite the survival rate being lower, a significant improvement took place and it rose from 4% (China) and 72% (Sweden) between 1995-1999 to 33% in Bulgaria and 78% in Germany. These significant improvements in survival are probably due to recent improvements in diagnosis and treatment. The authors also highlighted that in countries such as Germany and Austria, survival rates have remained consistently high due to greater adherence to treatment protocols.
The probability of survival depends on the child’s age at the time of diagnosis. In general, children aged 1 to 9 years have a higher survival rate for both types of leukaemia than those aged 10-14 years or those aged less than 1 year. Survival rates have improved in all age groups, especially for children with ALL aged from 10 to 14 years, while for children aged under 1 year it continues to remain low.
Data from Spain
In Spain, the survival rates for childhood leukaemia come from population records of 1,487 children that form part of the Spanish Network of Cancer Records (Red Española de Registros de Cáncer - REDECAN) and that participated in the CONCORD-2 study: Albacete, Asturias, Basque Country, Cuenca, Girona, Granada, Mallorca, Murcia, Navarra, Tarragona, and the Spanish Register of Childhood Tumours (Registro Español de Tumores Infantiles - RETI-SEHOP). The net 5-year survival rate of children with ALL increased from 74.1% to 84.2% during the periods 1995-1999 and 2005-2009, while for children with AML it increased from 47.3% to 60.2%
Reducing worldwide inequalities
According to Dr Audrey Bonaventure, from the London School of Hygiene & Tropical Medicine and principal author of the study, “there is still room for improvement in the management of childhood leukaemia in many countries. Optimum treatment offers the possibility of survival in the majority of cases. Furthermore, additional resources, as well as evidence-based initiatives, such as international collaboration and treatment guides, could improve access to efficient treatment and quality care for these children, which would contribute towards substantially reducing worldwide inequalities in survival.”
For Professor Phillipe Autier, from the University of Strathclyde Institute for Global Public Health, these improvements are the result of the combined effects of many factors, such as the increase in the precision of the diagnosis and the progress made in the care of ill children, including support care for children and their families. He also notes that high survival rates in countries with high incomes should not divert attention from the fact that 80% of childhood leukaemia cases occur in countries with few resources. “The adoption of locally adapted and accessible multi-disciplinary treatment programmes in countries with low and intermediate resources will probably result in improvements in the overall survival rates of children with leukaemia.”