Why children's research assent matters: Exploring three dimensions of autonomy.

Children's assent is an ethical and legal requirement for research that involves them. Nevertheless, studies suggest that children with cancer are not always involved in research decisions. This raises important ethical questions about how children's participation in assent should be supported and on what ethical grounds. In this paper, we explore three dimensions of autonomy in research with children: autonomy as a right, as a value, and as relational. We argue that it is important not only to respect children's autonomy but to also promote it as a value, by actively supporting children's autonomy. Central to this approach is an understanding of how relationships and trust can both enable and constrain children's autonomy. We suggest that children's autonomy may be supported in practice through capacity-sensitive participation, child-adapted and iterative information provision. This requires ongoing dialogue that is responsive to children's emotional, cognitive, and relational contexts, with particular attention to fears, decision-making challenges, and voluntariness. While concern for the well-being of children with cancer is essential, it should not be used as a justification to exclude them from the assent process. Respect for children as persons should guide recruitment to paediatric oncology research.