The primary objective of this study is to validate the Gross Motor Function Measure Scale-88 (GMFM-88) on the Italian pediatric cancer population. The secondary objective is to implement the use of the GMFM-88 in clinical practice by validating a reduced panel of items that will be called the Functional Ability Assessment in Pediatric Oncology (FAAP-O) Scale.

In recent decades, improvements in the treatment of pediatric cancer patients have resulted in increased survival rates. Consequentially, clinicians now pay more attention to the quality of life of these patients, both during and after treatment. Functional abilities have an important role in the quality of life and these skills can be compromised by the tumor itself or by anti-neoplastic treatments. A recent Cochrane review regarding rehabilitation and motor activity in this population has documented the effectiveness of exercise in children with cancer. Furthermore, to improve the rehabilitation care of pediatric cancer patients it is important to broaden the research by structuring multi-center trials, which allow the collection of longitudinal data. Objective, repeatable, specific, and sensitive rehabilitation assessment tools are needed, to define the functional status of the patient and to measure the motor outcomes. The psychometric properties of a measurement are closely linked to the specific population in which the measurement is used. Currently, there are two validated assessment tools for children/adolescents with cancer used to evaluate functional abilities: The Gross Motor Function Scale-Acute Lymphoblastic Leukemia (GMFM-ALL) and the Motor Performance in Pediatric Oncology (MOON). The ladder has the merit of being structured to evaluate the motor skills of children/adolescents affected by various forms of cancer but it also presents some limits. This test does not investigate functional abilities in a rehabilitation optic and it requires the use of specific materials that can reduce its usability in multicenter trials. The GMFM-ALL scale is a modified version of the Gross Motor Function Measure 88 (GMFM-88) Scale. This scale is specific only for children/adolescents with Lymphoblastic Leukemia and it mainly evaluates motor skills that require a high functional level (i.e. jumps, running), possessed neither by younger children nor by those who show major physical impairments or during specific phases of cancer treatment, such as palliative care.

The GMFM-88 scale is a rehabilitation assessment tool that was originally created to investigate functional abilities in children affected by cerebral palsy (CP) and has subsequently been validated for other populations of pediatric patients. It was also used to evaluate functional abilities in some studies conducted on pediatric cancer patients. Some aspects make this tool easily applicable in multicenter studies: it does not require any material to be administered nor a specific certified training to use it and, lastly, it comprises all principal motor skills including the basic ones (i.e. lying and rolling on the ground).

Inclusion Criteria:

• age between 6 months - 17 years and 11 months
• diagnosis of oncological disease
• being during antineoplastic treatment or up to 1 year off-therapy
• Written informed consent from patient or parents/legal representative, and age-appropriate assent.

Exclusion criteria:

• Patients that are not able and willing to comply with study visits and procedures.

Children and adolescents affected by cancer referred to the rehabilitation services of the participants centres.