Letter to the editor - reply.

To the Editor: We are in complete agreement with Dr. Spreafico et al. who have stated in their recent letter to the editor [1] that unfounded exercise restrictions for children with cancer enlarge the already severe burden of disease and treatment, and therefore have to be avoided by all means. When we recognize restricted physical activity levels as an additional burden of cancer disease and anti-cancer therapy, it seems to be an obligation to implement exercise programs during acute in-hospital and outpatient cancer treatment as we already concluded in our recent review [2]. There are a few aspects we would like to add regarding the framework conditions of sports promotion in pediatric oncology. The authors name the oncologist as the expert to provide information and guidance on how to exercise safely and effectively. Practice, however, has shown that a general recommendation to be physically active from oncologists is important to motivate patients, but detailed exercise programs should be developed and supervised by experienced sports professionals. The wide heterogeneity of tumors, physical limitations, and child-specific interests and motivations to be physically active requires recommendations and interventions that are adapted individually to (i) the previous experience in sports, (ii) individual aims and motivations during anti-cancer therapy, (iii) medical and general physical condition, and (iv) age-related contents of physical education at school. The prime motives behind exercise promotion differ among children and adults with cancer, because in pediatric oncology we especially pursue a pedagogical approach. Integrating contents of physical education into hospital routine may be an important step to promote motor development and maintain normality that patients aremissing due to exclusion from school during treatment. Exercise interventions should therefore also include child-oriented sensorimotor and coordination training in addition to cardiovascular, strength and relaxation training and stretching to improve balance skills, minimize risk for falls, and stimulate coordinative skills that are essential for a healthy motor development and tasks of daily living. The specific benefits and risks of exercise training for children and adolescents with cancer have not been determined in detail yet. We do not know, if aerobic exercise really has a cardioprotective effect against cardiotoxic chemotherapy like doxorubicin, as it could have been shown in animal models [3] or if it may even worsen cardiac function when conducted at the wrong point of time or with inadequate intensity. This example prefigures the ambiguity of sports in the context of cancer disease and points out the fundamental question we should be asking ourselves whenever we conduct exercise training: Are we offering sports to minimize disease related deficits or notwithstanding the deficits to respect the children’s right to sports promotion? In conclusion, there is no reason not to offer supervised exercise programs for children and adolescents with cancer. However, exercise programs should always be conducted in an interdisciplinary team, and future work should focus on structured recording of exercise related risk factors and potential benefits for pediatric cancer patients. This may help to develop exercise recommendations for children with different preconditions and therapy regimes and in the long term minimize the general burden of cancer disease.