International exchanges in the Butterfly program
13 maart 2026
What does a family need when a child is diagnosed with cancer? And how can we better predict which children will develop complications after a stem cell transplantation? Two PhD candidates within the EU-funded Máxima Butterfly program are taking concrete steps to make care more personal and targeted. They are not doing this alone at the Máxima, but are actively collaborating with other organizations in the Netherlands and abroad.
Psychologist Marnik Paeps studies how healthcare professionals can support parents at the time of diagnosis using a targeted questionnaire, shortly after diagnosis. This questionnaire gives insight into families’ concerns, stress factors and what type of support the family may need.
Molecular biologist Hannah Kunstek focuses on what happens inside the child’s body. She analyzes how immune cells recover after a stem cell transplantation and investigates why some children develop severe complications. Although their research differs greatly in approach, they share the same goal: to improve the support and treatment of children with cancer and their families.
As part of the Butterfly program, Paeps and Kunstek also completed an international research secondment in another research group. Marnik conducted research in the United States, where he gained new insights into implementing questionnaires in clinical care. Kunstek worked in the Czech Republic, where she learned an advanced technique to analyze immune cells in depth. Both now apply this knowledge directly in their own research at the Máxima, strengthening international collaboration in the field of childhood cancer.
The Butterfly project is made possible thanks to Horizon Europe/Marie Skłodowska-Curie COFUND project number 101081481, the Princess Máxima Center and the participating research groups. The Rene Vogels Foundation contributed to making Kunstek her secondment possible.
International exchanges
Better support for parents from the moment of diagnosis
Each year, approximately six hundred children in the Netherlands hear that they have cancer. This diagnosis turns family life upside down. Parents face not only medical questions, but also anxiety, uncertainty and practical concerns that require immediate attention.
Marnik Paeps has been working for over two and a half years as a PhD candidate in the Grootenhuis group. He is committed to structurally implementing a psychosocial questionnaire (Psychosocial Assessment Tool - PAT) at every new diagnosis. The Psychosocial Assessment Tool (PAT) screens for psychosocial risk in families of a child with cancer by assessing areas such as family resources, emotional distress, social support, and child behavioral functioning. It helps care teams identify which families need universal, targeted, or intensive psychosocial support early in the treatment trajectory.
Paeps: ‘A cancer diagnosis is one of the most life-changing moments in a parent’s life. By gaining insight at an early stage into what is happening within a family, even before treatment starts, we can provide the most appropriate support from the very beginning.’
During a secondment with Prof. Anne Kazak at Nemours Children’s Hospital in the United States, Paeps studied barriers to using the instrument and now applies these insights to strengthen psychosocial care for families during an exceptionally challenging period. Although this screener is already used among other questionnaires at the Máxima, he aims to improve the implementation process making targeted psychosocial care possible.
Discovering immune biomarkers after stem cell transplantation
Hannah Kunstek is a PhD candidate in the Nierkens group, where she studies immune recovery in children who undergo stem cell transplantation. While this treatment can be lifesaving, about one-third of the children develop graft-versus-host disease, a severe complication in which donor cells attack the child’s own body. Graft-versus-host disease has a standard treatment, but some children remain difficult to treat.
‘We need to better understand what exactly goes wrong and why it happens,’ Kunstek says. ‘With this project, I aim to identify immune biomarkers that can give us a clearer picture of why some children don’t respond to the standard graft-versus-host treatment.’
Her research is part of the PIKACHU study and uses advanced immunoprofiling techniques to map the phenotype and function of immune cells in detail. During a secondment with Prof. Dr. Tomas Kalina at Charles University in Prague, she learned to work with CYTOF technology, which allows highly detailed analysis of intracellular signaling pathways.
By combining CYTOF with genetic techniques such as single-cell sequencing, Kunstek is uncovering cell signaling patterns that could guide clinical monitoring. In future, Kunstek hopes this could help pick out children for whom standard treatment is unlikely to work. ‘If we know this earlier, we may be able to switch to another treatment sooner,’ she explains. With her work, Kunstek aims to contribute to higher survival rates and a better quality of life for children with cancer who undergo stem cell transplantation.