For decades, there has been a drive in medical research to develop ‘kinder ’ treatments for cancer. ¹ Recently, the James Lind Alliance have named finding “effective and kinder” treatments one of their top ten research priorities in childhood cancer. ² However, there is no guidance or definition on what a ‘kind’ treatment really is, beyond an understanding of a more tolerable experience of therapy. In children’s cancer, the meaning of ‘kinder’ treatments is subjective, and may differ for healthcare professionals and families, depending on what is considered important to the short- and long-term health and wellbeing of the child or young person.

Today, when presented with multiple treatment options, families with a child with cancer may have to make difficult and complex decisions on which option to take. This involves balancing the outcomes of treatment against the potential impact on the health and wellbeing of the child both during and after the treatment finishes. ^{3, 4} Families generally rely on their paediatric oncology team for information to aid their decisions but may seek additional information from other families with lived experience, or from online. ⁵

The concepts of treatment intensity, burden of therapy, severity, frequency, and consequence of side effects have been described and are used variably in clinical trials and clinical practice. ^{6– 12} However, how families, children and young people affected by cancer understand them in light of the concept of ‘kindness ’ is unclear. Having a method to present the ‘kindness ’ of different treatments from the perspective of the child and their carers, could help families compare alternative treatment decisions, based on their individual circumstances. Understanding the concept of the ‘kindness ’ of treatment, will help drive research efforts to find treatments that really are ‘kinder ’ than others. We can envisage a world where ultimately, ‘kindness’ becomes a quantifiable facet which attempts to identify and capture additional factors that families consider when making decisions about treatment that are not accounted for by other measures (such as adverse event profiles or quality of life measures).

In order to understand how ‘kindness’ could be used to aid treatment decision making for families of children with cancer, further research is needed into what ‘kind’ cancer treatment means to the paediatric oncology community. Therefore, this rapid review aimed to identify relevant tools that have been developed to measure the ‘kindness’ of cancer therapies.

Searches were conducted in April 2023. From 1485 records retrieved from database searches, 32 were deemed eligible after title and abstract screening. Following full-text screening, no studies met the inclusion criteria – that is, reported a measurement tool that assessed the ‘kindness’ of a cancer treatment. Figure 1 shows the PRISMA diagram of the screening decisions made in this rapid review. Studies were primarily excluded for being the wrong publication type (n = 20) and study design (n = 9). Two studies were excluded as they were investigating the wrong concepts; these studies looked at human ‘kindness’ and best supportive care.

The aim of this review was to determine whether there were any scales or measures to evaluate the ‘kindness’ of cancer treatments. In this review, no published study or measure was identified. The ‘emptiness’ of this review highlights that there are important knowledge gaps in the literature surrounding what ‘kindness’ means with regards to cancer treatments, and how this might be operationalised in a way that could be used by clinicians and families to inform their treatment decisions. ¹⁴

Given the absence of studies regarding ‘kindness’ measures or scales, we instead conducted a post-hoc exploration of how studies included at full-text screening had used the term ‘kindness’ to describe cancer treatments. In these studies, ‘kindness’ was primarily used to describe treatments that were less invasive or had fewer toxicities or were associated with less long-term effects. Many of the records used the word ‘kindness’ without context, highlighting a presumed understanding about what ‘kind’ cancer treatments are.

For members of this study’s PPI group, the concept of a ‘kinder’ cancer treatment stretches beyond the toxicities associated with a treatment, and encompasses other aspects of the treatment, for example, whether the treatment can be given at home, or how the treatment affects other aspects of a child’s life, such as sleep or whether they can attend school. Our PPI group told us that these alternative concepts of ‘kindness’ are critically important for families to consider when making decisions about treatment, and are typically not reported in protocols or publications of clinical trial results.

Given the lack of studies conceptualising the notion of ‘kindness’, future research in this area should begin by focusing on understanding what ‘kindness’ in paediatric oncology treatments means to families and clinical practitioners. This could, in turn, inform the development of an assessment tool that includes important aspects to treatment not yet captured in measures of quality of life or adverse events, for example.

The searches for this study were limited to only focus on the word ‘kindness’ in the cancer literature, rather than expanding it to look at broader definitions. This was a purposeful decision, to ensure that our own perceptions on what ‘kind’ treatments are did not influence what was identified.

Owing to resource and time constraints, this research used rapid review methods, which could have resulted in some potentially eligible studies not being identified. While the title and abstracts were screened by two reviewers in duplicate, full-text screening was completed by one reviewer which could have potentially meant there were errors or potential bias in study selection.

This rapid review aimed to identify studies of measures or scales that evaluated the ‘kindness’ of cancer treatments. However, no studies of this nature were identified highlighting an important research gap that should be explored further.

“ Can we find effective and kinder (less burdensome, more tolerable, with fewer short and long term effects) treatments for children with cancer, including relapsed cancer?” was recently named as the top priority for research in children’s cancer by the James Lind Alliance, ² emphasising the importance of this concept for families and clinicians. Research should focus on understanding what ‘kind’ cancer treatment means to the paediatric oncology community, and consider developing a ‘kindness’ tool that could aid treatment decision making for families of children with cancer.

SC leads a charitable fund for rhabdomyosarcoma research as Special Named funds within the Children’s Cancer and Leukaemia Group (CCLG). This is representative of many families with experience of childhood cancer, where fundraising and research advisory roles often co-exist. The authors have no other conflicts of interest to report.