For this study, Ardine Reedijk, who conducted the research with pediatric oncologist Prof Dr Gertjan Kaspers and epidemiologist Dr Henrike Karim-Kos (among others), used data from the Netherlands Cancer Registry that has been collected nationally since 1990. The study revealed that the chance of curing AML increased from 40 percent in the early 1990s to 74 percent in the latest period measured - from 2010 to 2015.
The researchers placed the data from the Netherlands Cancer Registry alongside those of SKION (Stichting Kinderoncologie Nederland). In their data comparison, they zoomed in on the progress made in treating children and young adults in the areas of incidence, survival and death.
Incidence
The incidence of AML (the number of new cases of the disease) increased slightly among 1- to 4-year-olds, tells Ardine Reedijk. "That is primarily because slightly more children are being diagnosed with cancer to begin with. If you look at all forms of cancer in both children and adults, the number of cases increases by 1 percent per year. The increase in this specific age group could be explained in part by the relatively high number of children with Down syndrome in the Netherlands."
Risk of death
In the study, researchers established that the Netherlands has made demonstrable progress in the treatment of childhood AML. The mortality rate is decreasing by 2.8 percent each year. The risk of death according to the most recent protocol fell by 49 percent. What exactly causes this, is something the researchers cannot pinpoint precisely. They explain it as a combination of factors, including improved diagnostics, better use of chemotherapy and improved supportive care, and better therapy when AML returns (a relapse).
Treatment protocols
The treatment regimens are different, notes Gertjan Kaspers. "We now know a smidgen better which children are at a higher risk of recurrence. In those cases, we adapt another course of treatment by, for example, scheduling it closer to the first course. It is not so much about new medication, but we do have a better understanding of when to give higher or lower doses. We also examine the properties of the leukemia cells. By zooming in on these cells in the bone marrow, we can make predictions about their behavior. Adapting and improving treatment protocols is an ongoing process for us."
In addition, the study found that children are less likely to dye from side effects. Serious side effects, such as inflammation and lung damage, were more often the cause of death in children in the past. "Back then, I remember talking about 10 to 15 percent of the children," according to Kaspers. "Now it is just a few percent."
The scientific publication can be found here: Reedijk AMJ, et al. Improved survival for children and young adolescents with acute myeloid leukemia: a Dutch study on incidence, survival and mortality. Leukemia. 2019 Jun;33(6):1349-1359.