Over the last decades, research has shown that poor nutritional status can adversely impact prognosis and increase toxicities during treatment for childhood cancer. EPICkids is a collaboration between the International Initiative for Pediatrics and Nutrition, the International Agency for Research on Cancer, and sites throughout three Southern European countries (Spain, Greece, and Italy). The primary aim of EPICkids is to establish an informational resource on critical nutrition parameters wherein we can describe the trajectory of nutritional status among Southern European children and adolescents with acute lymphoblastic leukemia (ALL) and favorable biology brain tumors, investigate lifestyle behaviors, sociodemographic factors, and quality of life and correlate these indicators with clinical outcomes. The specimens obtained with the proposed study will foster future studies on nutrition and prevalent childhood cancer as well as establish a framework to develop evidence-based guidelines for European children with cancer, utilizing regional, European data. We plan to recruit 900 patients with ALL and 1400 patients with a favorable biology brain tumor over five years. Nutrition parameters and lifestyle factors will be measured at systematic timepoints over the study period. Stool and blood specimens will be collected at each timepoint. Eligible patients will be between 3 and 21 years of age.

Over the last decades, research has shown that poor nutritional status can adversely impact prognosis and increase toxicities during treatment for childhood cancer. EPICkids is a collaboration between the International Initiative for Pediatrics and Nutrition, the International Agency for Research on Cancer, and sites throughout three Southern European countries (Spain, Greece, and Italy). The primary aim of EPICkids is to establish an informational resource on critical nutrition parameters wherein we can describe the trajectory of nutritional status among Southern European children and adolescents with acute lymphoblastic leukemia (ALL) and favorable biology brain tumors, investigate lifestyle behaviors, sociodemographic factors, and quality of life and correlate these indicators with clinical outcomes. We will also create a prospective biorepository of specimens (stool, blood) obtained at diagnosis, during treatment, at the end of treatment, and after treatment among children and adolescents undergoing treatment for ALL and favorable biology brain tumors. We plan to recruit 900 patients with ALL and 1400 patients with a favorable biology brain tumor over five years. Eligible patients will be between 3 and 21 years of age receiving standard treatment at one of the participating institutions. Data will be collected at systematic timepoints over the study period and include demographics, food security, clinical data and disease characteristics, quality of life, physical activity, dietary intake, and nutritional anthropometric data. Blood and stool specimens will be collected at each timepoint throughout the study period.

Inclusion Criteria:

Age: ALL and favorable biology brain tumors: Patient must be between 3 years and 21 years of age at the time of consent.

Diagnosis:

• ALL: Patients must have newly diagnosed B-cell ALL, T-cell ALL, or mixed phenotype acute leukemia confirmed by immunophenotyping by flow cytometry.
• Brain tumors: Patients must have newly diagnosed favorable biology brain tumor confirmed by either pathology report, imaging and/or biochemical studies including low-grade gliomas, medulloblastoma, ependymoma, pituitary tumors, germ cell tumors.

Treatment:

• ALL and brain tumors: Participants may be children on a clinical trial or "as per" a clinical trial.
• ALL: Patients will receive standard leukemia treatment.
• Brain tumors: Patients will be treated depending upon standard approach with surgery, chemotherapy, radiation therapy. Patients receiving autologous stem cell transplantation as part of their regimen may be included.

Location: ALL and brain tumors: Patients must be receiving treatment at one of the participating centers.

Timing:

• ALL: Parents/guardians must consent and patient assent, if applicable, within three working days of diagnosis.
• Brain tumors: Parents/guardians must consent and assent, if applicable, prior to initiation of chemotherapy, radiation or stem cell transplant.

Exclusion Criteria:

ALL and brain tumors:

• Patients with relapsed or progressive disease, exclusive of patients with unresectable low-grade gliomas who have progressive disease.
• Patients with history of other primary malignancy.
• Patients with other medical conditions not associated with the malignancy that may interfere with nutritional status/growth and/or microbiome composition, like patients with Down's syndrome, metabolic disorders or celiac disease. Patients with genetic predisposition that may interfere with nutritional status/growth.

ALL:

• Patient plans to receive hematopoietic stem cell transplant.
• Mixed lineage leukemias who receive AML-based protocols. Brain tumors: Children/adolescents who will be managed by observation or surgery only, or diagnosed with ATRT or high-grade gliomas.

Southern European children and adolescents ages 3-21 years of age with acute lymphoblastic leukemia and favorable biology brain tumors.