To collect information about the patient's leukemia and to seek the optimal treatment for children with ALL based on the individual level of risk of the cancer coming back after treatment. The risk groups are defined as a result of recent research conducted by the Children's Oncology Group (COG). We would like to learn if the use of an experimental intrathecal therapy (ITT), which has been given to many people with ALL and has been well tolerated, would be better at preventing relapse in the central nervous system and improve disease outcomes in children with High Risk ALL.

Ependymoma is a type of rare childhood cancer that occurs in the brain and spinal cord. Survival statistics are generally disappointing with a 5-year survival of 50-64%. The standard of care for ependymoma is maximal surgical resection followed by radiation therapy directed at the primary site of disease.

Radiation therapy is associated with immediate and long-term toxicities in children, especially young children. For this reason, it has been the practice of some doctors not to give radiation therapy to children with ependymoma when the tumor has been completely surgically removed. The investigators who designed this study have created strict measures to choose those who will not receive additional treatment after surgery and careful follow-up to minimize the risks to those who are assigned to observation only.

the United States, it is standard treatment for patients with high-risk neuroblastoma (NBL) to receive the drugs carboplatin, etoposide and melphalan (CEM) as the preparative regimen in Consolidation therapy prior to Autologous Stem Cell Transplant (ASCT). BuMel Consolidation therapy has recently been studied in patients with high-risk NBL in some European countries. The findings from those studies indicate that the use of BuMel prior to ASCT may be linked to an increase in the survival rate for patients when compared to CEM. Those studies also indicate that the chance of the disease coming back (a relapse) may be lower among the patients who received BuMel Consolidation therapy. In North America the BuMel combination is considered experimental. In this study, researchers want to find out if a combination of busulfan and melphalan (BuMel) can be given as Consolidation therapy prior to ASCT for subjects with newly diagnosed high-risk NBL. The main goal of this study is to find out what effects, good and/or bad, a BuMel preparative regimen given before ASCT has on people with newly diagnosed high-risk NBL.

The overall goal of this study is to find out what effects, good and/or bad, a low
dose and a high dose of lenalidomide have on children, adolescents and young
adults with recurrent (has come back after being treated), refractory (has not gone
away with previous treatment), or progressive (is not responding to previous
treatments) Juvenile Pilocytic Astrocytomas (JPA) and Optic Pathway Gliomas
(OPG).

This study is for patients that have been diagnosed with High Risk B-Lymphoblastic Leukemia (HR B-ALL). The investigational drug in this study is Ruxolitinib. The purpose of this study is to find out if the study drug, ruxolitinib, in combination with standard HR B-ALL treatment is safe and effective in children, adolescents, and young adults with HR B-ALL. Participants can expect to be in this study for the treatment period of approximately 26 months (females) or 38 months (males) plus the post-treatment follow-up. Subjects are considered on study during the post-treatment follow-up period until the subject is deceased, lost to follow-up, or until the study is completed. Subjects in this study will be followed until all enrolled subjects have been followed for 3 years from Day 1 or are deceased or lost to follow-up.

This study is for patients who have been diagnosed with a form of Acute Lymphoblastic Leukemia (ALL) called Philadelphia chromosome positive (Ph+) ALL. The purpose of this study is to compare disease free survival (DFS) of Standard Risk (SR) pediatric Ph+ ALL treated with continuous imatinib combined with either a high-risk COG ALL chemotherapy backbone or the more intensive EsPhALL chemotherapy backbone. A drug called imatinib in combination with chemotherapy will be given. Participants can expect to be in this study for up to 2 years and their health followed for up to 10 years.

This study is for patients that have been diagnosed with Germ Cell Tumors. The purpose of this study is to evaluate whether a strategy of complete surgical resection followed by surveillance can maintain an overall survival rate of at least 95.7% at two years for pediatric, adolescent and adult patients (ages 0- 50 years) with Stage I (low risk) malignant germ cell tumors, and at least 98% for patients with ovarian pure immature teratoma. The drugs used in this study are carboplatin and cisplatin. Participants will be followed for up to 10 years.

This study is for patients that have been diagnosed with Leukemia or Lymphoma. and have been treated on one of the following studies: Pediatric Oncology Group (POG) 9404, 9425, 9426, or Dana Farber Cancer Institute (DFCI) ALL Consortium 95-01. The purpose of this study is to look at the heart function of patients selected by change to get DRZ compared to the heart function of patients selected by chance not to get DRZ. In this study, they will also look at gender, age at cancer diagnosis, current age, dose of chemotherapy, and if chest radiation influences the risk of early heard damage. Participants in this clinical trial are expected to come to one clinic visit.

This study is for patients that have been diagnosed with multisystem Langerhans cell histiocytosis (LCH). The purpose of this study is to find out if prolonging the treatment and adding a drug called 6-mercaptopurine will be beneficial. Other goals include fining out if these changes will result in fewer patients having relapse of their LCH, and fewer patients having long term disease related problems. Participants can expect to be in this study for up to 24 months and will be followed on this study fir at least 5 years.

This study is for patients that have been diagnosed metastatic germ cell tumors. This study will compare the standard chemotherapy regimen with an accelerated chemotherapy regimen using the same drugs to see if the accelerated chemotherapy regimen is beneficial but not more toxic than the standard chemotherapy regimen. The accelerated chemotherapy is experimental. Participants can expect to be on study for about 3 months and continue to be followed for up to 5 years.