This study is for newly diagnosed or previously untreated low-grade glioma (LGG). The overall goal of this study is to see if selumetinib works just as well as the standard treatment using carboplatin and vincristine (called CV) for subjects with LGG. Selumetinib is a drug that works by blocking a protein (a basic building block of the human body) that lets cancer cells grow without stopping. Participants can expect to receive treatment on this study for about 1–2 years. After study completion, participants will continue to be followed for up to 10 years.

This study is for patients that have been diagnosed with non-germinomatous germ cell tumor (NGGCT). The goal of this study is to see if radiation therapy (RT) to the spine and a portion of the brain works just as well as the standard treatment, which includes RT to the whole brain and spine, for people with NGGCT who agree to take part in this study, and whose disease responds well to induction chemotherapy, or who have no signs of disease following surgery. Participants can expect to receive treatment on this study for about 6 to 11 months, depending on which therapy they receive. After study completion, participants will continue to be followed for up to 10 years.

This study is for newly diagnosed previously untreated neurofibromatosis type 1 (NF1) associated with low-grade glioma (LGG). The purpose of this study is to see if selumetinib works just as well as the standard treatment of carboplatin/vincristine (CV) for subjects with NF1-associated LGG, and to see if selumetinib is better than CV in improving vision in subjects with LGG of the optic pathway. Participants can expect to receive treatment for up to 24 months, until the cancer gets worse or until the side effects are too great. After study completion, participants will continue to be followed for up to 10 years.

This study is for patients that have been diagnosed with leukemia. This study is called a screening study and we are doing this study to find better ways to diagnose and treat leukemia in children, adolescents and young adults. Bone marrow, blood, and medical information about participant's cancer and treatment will be collected. Participants can expect to be on this study for 5 years.

This study is for patients that have been diagnosed with relapsed/refractory neuroblastoma. The investigational drug given is eflornithine (DFMO) along with etoposide. DFMO is the investigational drug being used along with etoposide for treatment of neuroblastoma. Participants will undergo a number of standard tests and research-related procedures before being able to enroll in this study. Some risks include but are not limited to: fewer red and white blood cells, diarrhea, abdominal pain, loss of appetite, skin rash, seizure, difficulty swallowing and blurred vision. Participants can expect to be on this study for approximately 2 years. Participants will then be followed for up to 5 years after study completion.

This study is for patients that have been diagnosed with early-stage (Stage I or II) Hodgkin lymphoma (HL)(cHL). The main purpose of this study is to compare the effects, good and/or bad, of brentuximab vedotin and nivolumab (Bv-NIVO) against standard therapy for people with HL to find out which is better. Participants can expect to be in the study for up to 54 months.

This study is for patient that have been diagnosed with rhabdomyosarcoma (RMS). The investigational drug in this study is vinorelbine, vincristine, dactinomycin, and cyclophosphamide (together called VINO-AC with vincristine). The purpose of this study is to compare the effects, good and/or bad, vinorelbine has on people with high risk RMS. Also, to find out if adding maintenance therapy will help get rid of the cancer and/or lower the chance that the cancer comes back. Participants can expect to be in this study for 12 months and will include chemotherapy, radiation and possibly surgery.

This study is for patient that have been diagnosed with High Risk Neuroblastoma. The investigational drug in this study is naxitamab. The purpose of this study is to test the safety of adding an Anti-GD2 Immunotherapy agent (naxitamab) to your standard therapy during the induction phase of care. Read the sections on risks and benefits carefully and be sure you understand them. This study will also look at the effectiveness of this treatment.