Donor Stem Cell Transplant After Chemotherapy for the Treatment of Recurrent or Refractory High-Risk Solid Tumors in Pediatric and Adolescent-Young Adults

This phase II trial investigates side effects and how well donor stem cell transplant after chemotherapy works in treating pediatric and adolescent-young adults with high-risk solid tumor that has come back (recurrent) or does not respond to treatment (refractory). Chemotherapy drugs, such as fludarabine, thiotepa, etoposide, melphalan, and rabbit anti-thymocyte globulin work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving chemotherapy before a donor stem cell transplant helps kill cancer cells in the body and helps make room in the patient's bone marrow for new blood-forming cells (stem cells) to grow. When the healthy stem cells from a donor are infused into a patient, they may help the patient's bone marrow make more healthy cells and platelets and may help destroy any remaining cancer cells.