Treatment for childhood cancer causes treatment-related acute adverse events such as muscle weakness and physical incompetence. With long admissions, isolation, and long-term bed rest, this means reduced physical activity and, ultimately, gross motor functioning development is affected. Furthermore, the children participate less in sport and leisure activities, inhibiting social skills, and the children feel isolated from peers. The above makes it difficult for children to return to everyday activities. Physical activity in the form of play and movement activities is essential for preschool children's gross motor, social, and personal development- a development where parents play a crucial role.

Replay is a randomized controlled trial that will include 84 children with cancer aged 1-5 years at the University Hospital Copenhagen, Rigshospitalet. The children are included at the treatment initiation and are randomized to either the intervention group or the control group. The intervention consists of six months of daily structured play-based physical activity, including daily parent administered play and movement and three weekly group-based play and movement sessions at the hospital during admissions. Gross motor and physical function is measured with 1) Peabody Developmental Motor Scales, Second Edition (PDMS-2), Pediatric Evaluation of Disability Inventory (PEDI), Handgrip strength, and a six-minute walk test. The assessment time points are baseline (initiated timepoint), 3- and 6 months (endpoint) after initiated treatment. The intervention group will be observed and invited to participate in qualitative interviews. The control group will receive usual care and specific physiotherapy if needed.

Aim

Project RePlay aims to investigate the effectiveness of a play-based physical activity intervention on gross motor functioning measured by Peabody Developmental Motor Scales, Second Edition (PDMS-2) with the primary end-point six months after diagnosis in children with newly diagnosed cancer aged 1-5 years old. The investigators hypothesize that the intervention will reduce short- and long-term physical and psychosocial consequences, including reduced gross motor function and lack of social interaction.

1. Background

   Physical play and movement activities are essential for preschool children's gross motor, social, and personal development. Through play and movement, children develop motor skills crucial for participation in physical and social activities throughout life. A study showed that an 18-week play intervention among healthy preschool children significantly improved (p<.0005) gross motor function in the intervention group compared with the control group. Play is also the children's first arena for socializing, and these interactions have an immense role in developing emotional, personal, and social skills. Physical play and movement activities are more than just physical exercise; it is social teamwork, emotions, and learning. Reduced physical activity or inactivity in children is highly dependent on three factors; 1) reduced dynapenia (muscle strength and power), 2) exercise deficit disorder (physical inactivity), and 3) physical illiteracy (reduced competence, confidence, and knowledge in movement). Due to more intensive treatment with chemotherapy, radiation, and surgery, children with cancer experience acute adverse events such as myopathy and neuropathy, resulting in muscle weakness, physical incompetence, and inactivity. Furthermore, treatment-related complications such as infections can cause extended periods of hospitalization, periods of isolation, and long-term bed rest. Thus, many children with cancer experience several physical side effects as impaired motor skills, physical capacity, and decreased motivation to engage in physical activity. The cancer treatment has a significant impact on the children's physical development and socialization as the lack of motor development leads to inactivity and less participation in sport and leisure activities. This leads to a reduced understanding of the social playing field in joint activities, and the children feel more isolated from peers. Children with cancer experiences challenges in all three factors leading to physical inactivity. Compared with siblings and the general population, these social and physical challenges persist for the rest of their lives. Hence, children diagnosed with cancer have lower school performance, lower education level, higher unemployment, and increased socioeconomic challenges. Thus, the investigators hypothesize that early initiated rehabilitation programs during initial treatment, focusing on maintaining a typical physical activity level, are crucial for continuing everyday activities during and after treatment.

   The rehabilitation, including social and physical activity and education in children and teenagers with cancer (RESPECT) study for children with cancer aged 6-18 years, showed that it is feasible to carry out physical tests and motivate them to participate in physical activities. Physical activity maintained the hospitalized children's physical fitness and gross motor function during treatment compared with hospitalized children who did not receive physical activity intervention. A systematic review covering international studies show similar findings; that physical activities positively affect mobility, physical fitness, muscle strength, and quality of life in children with cancer. Additionally, children with cancer who participate in structured physical activities during treatment have fewer admission days than children who received standard care, corresponding to a 17% reduction in hospitalization's total economic cost. Most studies focusing on physical activity as part of an early initiated rehabilitation program designed interventions for school children aged 6-18. Only a few of the studies include children under the age of 6 years. Each year 200 children and adolescents aged 0-18 years are diagnosed with cancer in Denmark. Of these, approximately one-third is diagnosed before the age of 5. None of the published studies on physical activity in pediatric oncology designed interventions for preschool children (1-5 years old). Thus, there is a lack of studies with an intervention designed for preschool children with cancer focusing on physical and social rehabilitation. Improvements in cure-rates of childhood cancer mean that today's 5-year survival is 85%. Thus, more research into the best strategies for physical activity and rehabilitation for all age groups of children with cancer is needed.

   A single study of parent-controlled physical activity at home included children with cancer from age 1-17. The intervention didn't improve the children's motor function compared with the control group, mainly due to poor adherence to the intervention. Project RESPECT shows that motivation and adherence to physical activity interventions are dependent on the support from "significant others" such as parents and exercise professionals. Parents are an essential resource for children with cancer. The parents follow the child's treatment closely, and the parents' support throughout the treatment is crucial for the child's need for presence and support so the child can feel safe and in control. Furthermore, the focus on home-based care is increasing to minimize hospital visits. Consequently, parents play an essential role in physical activity and rehabilitation for children with cancer. For preschool children, the parents' role is even more essential. When small children and parents play together, it creates a unique and safe environment where the children can be challenged physically and socially. Children's development is dependent on parents, and parents of a child with cancer must acquire the necessary skills concerning play and movement for the child.

   With project RePlay, the aim is to develop prophylactic strategies by investigating a play-based physical activity intervention for children with cancer aged 1-5 years to ensure the retention of natural motor and social development and participation in everyday activities. The hypothesis is that individual and social play and movement activities, with parents as resources, can reduce gross motor and social development impairments. Thus, the objectives of RePlay are:

   • To investigate the effects of a six-month play-based physical activity intervention in children with cancer, aged 1-5 years on gross motor function compared with a control group receiving usual care.
   • To investigate the children with cancer and the parents' experiences with a play-based physical activity intervention during treatment and the influence on the children's social and personal development.

2. Research plan

Design:

The randomized controlled trial study takes place at the Department of Pediatric Hematology/Oncology at Rigshospitalet. RePlay will include 84 children aged 1-5 years diagnosed with cancer. The children are randomized to either the intervention- or control group after the children have performed the baseline testing. The children will be stratified by age at inclusion (respectively, over and under three years old) and treatment group (hematologic malignancy, solid tumors, CNS-tumors). The intervention group will participate in a six-month play-based physical activity intervention starting from initiated treatment. The study will be an open-ended cohort where newly diagnosed patients are included on an ongoing basis.

The intervention will consist of 45 min daily play-based physical activities inspired by Mighty Moves from the study of Bellows et al. [5], where the activities are playful and focus on gross motor skills. The intervention combines hospital and home-based physical activity. Three days a week, there will be 45 minutes of group-based physical activity at the hospital for the children, siblings, and parents during admissions or appointments at the outpatient clinic. An exercise professional or pediatric physiotherapist administers the group-based sessions at the hospital. Children isolated in the hospital room are offered individual sessions as a substitute for the group-based sessions.

During the other four days a week or on days where the family is at home, the parents administer the play-based physical activity. The parents receive education and supervision on conducting play-based physical activity with their child in the hospital room or at home. The parents will receive inspiration material containing numerous different plays, games, and activities in different intensities, ensuring that their child is physically active every day with different intensity. The material is designed to engage the child in choosing what activities to do.

Due to age-specific development and movement, the children in the intervention group are split into two groups for the group-based sessions:

• Tumble: 1-2 years old • Tumble turbo: 3-5 years old

An example of a weekly schedule:

Monday: parent administered play

Tuesday: parents administered play OR group-based session at the hospital

Wednesday: parent administered play

Thursday: parents administered play OR group-based session at the hospital

Friday: parents administered play OR group-based session at the hospital

Saturday: parents administered play

Sunday: parents administered play

The control group will receive standard treatment and physiotherapy if needed. After six months of treatment, the child and parents will receive a status on the child's motor development and be invited to receive individual instructions and invited to participate in the social sessions.

Sample size:

Since there is no evidence on the potential effect of gross motor function in children with cancer, the sample size is estimated based on Bellows et al.'s (2013). The study objective was to research the potential of a play intervention on gross motor function in healthy preschool children measured by Peabody Developmental Motor Scales, Second Edition (PDMS-2). The sample size is estimated with an Alpha = 0,05 and Power = 80%. Based on a mean (SD) in the interventions group = 99,31 (9,07) and a mean (SD) in the control group = 93,24, n=70 (35 intervention group; 35 control group) are to be included. Assuming a 20% dropout rate, RePlay will include 84 children.

Inclusion Criteria:

• Children diagnosed with cancer or benign disorders and are being treated with chemotherapy and/or radiation and are admitted to the Department of Pediatric Hematology/Oncology at University Hospital Copenhagen, Rigshospitalet.
• Children at the age of 1-5,9 years at diagnosis.
• Children whose parents can communicate in Danish.

Exclusion Criteria:

• Children with mental disabilities that complicates the ability to follow instructions.