The purpose of this study is to determine whether early rehabilitation intervention including individualized physical training and social activities with a class mate at two weeks intervals at the ped.onc. center will increase children with cancer's level of physical performance

Background In Denmark 200 children under the age of 18 are diagnosed annually with cancer and the prevalence of patients undergoing anticancer therapy is 300. The expected five-year survival rate is 80%, but since the treatment is intensive with a high risk of life-threatening infections, these patients are frequently isolated at home or in hospital during their 1-2 years of therapy, which means reduced contact with their normal school environment, leisure activities and friends. Long-term survivors of childhood cancer frequently have compromised age-appropriate social relationships and psychosocial development, difficulties with resuming physical activities, and poor self-esteem leading to reduced quality of life. Intervention studies designed to improve physical and social function during treatment of children with cancer are lacking.

Aim To develop an interactive rehabilitation programme that a) preserve the educational, physical and psychosocial life of the patients or even obtains "growth with cancer", b) maintains the child's everyday life (e.g. normal social relationships), and c) improves long-term physical performance, social competences, higher grade educational enrollment, and later integration into the labour market.

Theoretical basis This project is inspired by Erving Goffman's interactional theory on normality and related concepts of stigma and frame analysis as well as Thomas Scheff's theory on the concept of emotional and social bonds and the development of the sociology of emotions.

Material and methods Intervention group: Children aged 6.0-18.0 years diagnosed with cancer 2013-2015 at Rigshospitalet (covers eastern part of Denmark (approximately 50% of total population)).

Control group:

The primary control group is children with cancer treated at the university hospitals in Odense, Aarhus and Aalborg 2013-2015.

In addition, outcome data for cases will be compared with three other (secondary) comparative groups: a) children with cancer treated at any Danish childhood oncology unit throughout Denmark in 2012 (historical controls); b) the sibling closest in age to the intervention group patients (family matched); and c) the intervention group patient's classmates.

Physical performance end point The physical performance will be monitored by: Andersen interval test, Timed up and go test, Sit to stand test, flamingo balance test, strength of hand by squeeze dynamometer and VO2 peak sub-max test.

Physical measures

Dexa scan

Questionnaires: PedsQL, Strength and Difficulties Questionnaire (SDQ), Revised Child anxiety and Depression Scale, Resilience, Loneliness and Social Dissatisfaction Questionnaire og The Children´s Impact of Event Scale 13.

Qualitative interviews: Qualitative interviews are performed with children with cancer, their parents, and the ambassadors. The focus will be on sociometric status, social independence and competences, self-esteem, fatigue, physical activity, educational outcome, and safety issues as well as an evaluation of the intervention program.

Outcomes and statistical considerations Provided all children with cancer (6-18 years) are included in the intervention or control group this study will be national cohort study including approximately 120 intervention children and 120 control children during the three year intervention period.

In relation to physical performance the power calculation is based on previous published small studies that found a baseline VO2peak of 24.3 (SD5.9) among children with ALL. If 120 children are included in the intervention and in the control group, then it the study will have a power or more than 0.85 to detect a 10% improvement and a power of 0.95 to detect a 15% improvement.

Inclusion Criteria:

• Children diagnosed with cancer and treated at the pediatric oncology units in Denmark (Rigshospitalet, Odense University hospital, Aarhus University Hospital and Aalborg University Hospital)

Children diagnosed with non-malignant diseases treated with surgery, chemotherapy or irradiation similar to cancer (e.g. benign CNS tumors, langerhans cell histiocytosis, Myelodysplastic Syndrome (MDS)) and treated at the pediatric oncology units in Denmark (Rigshospitalet, Odense University hospital, Aarhus University hospital and Aalborg University Hospital).

Attend school at the time of diagnosis

Able to communicate in Danish

Exclusion Criteria:

• Mental retardation at the time of diagnosis (including Down syndrome) Terminal illness at the time of diagnoses Severe co-morbidity