Stable incidence, improved survival, and reduced mortality are the results of the first population-based study in the Netherlands of children and young adults under 18 years of age with non-Hodgkin’s lymphoma, during the period 1990-2015. These are favorable outcomes, according to Dr. D. Henrike Karim- Kos, epidemiologist and principal investigator at the Princess Maxima Center for Pediatric Oncology in Utrecht and senior researcher at IKNL. Karim Koss is the initiator of the population study because epidemiological research has never been conducted in the Netherlands into incidence, survival, and mortality among children (0-14 years) and young adults (15-17 years) non-Hodgkin.
The researchers analyzed data on 1,001 children and young adults. The data come from the Dutch Cancer Registry (NKR). This provides an almost complete picture of the number of children and young adults diagnosed with Non-Hodgkin’s disease in the period 1990-2015. Karim Koss: “So the therapists could not provide parents with good information about the chance of survival for their children based on the Dutch data. There was US data, but it is not easily compared to our Dutch figures. In the US, children are often treated more intensively. Population composition also varies, and we know that some lymphomas are more common in certain populations.
The study distinguishes between the four most common subtypes of non-Hodgkin’s lymphoma: LBL, Burkitt’s lymphoma (BL), large B-cell lymphoma (DLBCL), and anaplastic large cell lymphoma (ALCL). “This subgrouping provides a lot of information,” says Karim Kos. BL, for example, is relatively more common in children up to 15 years of age. We see DLBCL more often in young adults aged 15 and over. These subtypes also differ in diagnosis and treatment, among others. Patients with LBL and BL were already doing well in the late 1990s, compared to patients with DLBCL and ALCL. The improvements are also the strongest for the last two groups. ‘
The study showed that the 5-year survival rate in children and adolescents with non-Hodgkin’s disease in the early 1990s was about 70 percent. This percentage rises to nearly 90 percent in the years 2010-2015. This improvement is due to many reasons, Karim Kos suspects. First and foremost, treatment protocols have changed since the late 1990s. Since then, less radiation has been given to treat lymphomas, because radiotherapy increases the risk of developing other tumors in the long term. Moreover, since 2004, practitioners are increasingly prescribing immunotherapy as a therapeutic intervention. Young people between the ages of 15 and 17 are often treated by a pediatric oncologist. We know that pediatric oncologists often treat more intensively than adult oncologists and this leads to better outcomes at the group level.
“This is not to say that adult oncologists are doing less well, but we have seen a much better 15-17-year-old survival since then,” says Karim Kos. “Especially in young adults with Burkitt’s lymphoma or diffuse large cell lymphoma. This better survival also leads to a lower death rate Karim Kos would have also liked to see a decrease in the incidence over the years It did not, the incidence has remained stable for years, with 38 children and young adults diagnosed as non-Hodgkin each year On the other hand, the incidence did not increase either.It is clear that the risk factors for non-Hodgkin have remained unchanged throughout these years.
Karim Koss sees the population study as a primary measure, as the first criterion for the quality of treatment in the Netherlands for children and young adults with non-Hodgkin’s disease. The study period, 1990-2015, was not chosen by chance. Then in 2018, the Princess Maxima Pediatric Oncology Center in Utrecht opened its doors. This led to more centralization in the diagnosis and treatment of lymphomas. The assumption is that centralization leads to better care, but you want to be sure. This is only possible if you have good comparison material. Hence this basic measurement.
Whether centralization of care at Princess Maxima leads to better outcomes for treating non-Hodgkin’s lymphoma in children and young adults must be established through follow-up research. We need new NKR data for this, which will be collected in the coming years. Of course we hope to be able to demonstrate that by increasing the focus of care, we will be able to raise the percentage of survival from 90 to 100 percent. It remains to be seen if that will work.
Read the full article:
- Reedijk, A.M., Beishuizen, A., Coebergh, JWW, Hoeben, B.A., Kremer, LC, Hebeda, KM, … & Karim-Kos, HE (2022). Progress against non-Hodgkin’s lymphoma in young children and adolescents in the Netherlands since 1990: stable incidence, improved survival, and decreased mortality. European Journal of Cancer, 163, 140-151.