Busulfan, Melphalan, Topotecan Hydrochloride, and a Stem Cell Transplant in Treating Patients With Newly Diagnosed or Relapsed Solid Tumor

Inclusion * Patients with relapsed neuroblastoma, rhabdomyosarcoma, Ewing's sarcoma, PNET, brain tumors, soft tissue sarcomas, Wilm's tumors, germ cell tumors or other solid tumors who achieved at least partial response (PR) to chemotherapy, surgery, or radiotherapy * Newly diagnosed patients for poor-risk pediatric solid tumors: metastatic Ewing's, metastatic PNET, rhabdomyosarcoma, soft tissue sarcomas, octeomesenchymoma, and others that are at a high risk of relapse and who have achieved at least partial response (PR) to chemotherapy, surgery, or radiotherapy * For any of the above categories, an attempt to achieve a complete response (CR) or PR should be made; pre-transplant modalities may include surgery, chemotherapy, or radiation therapy; radiation must not include lung fields; only patients in CR or PR at the primary site will be eligible * HIGH-DOSE CHEMOTHERAPY: Histologically confirmed diagnosis by Anatomic Pathology Department; if recurrent or metastatic disease, histologic confirmation should be obtained, with the exception of brain stem tumors; in neuroblastoma, demonstration of marrow metastases with elevated urinary catecholamines is adequate for diagnosis * HIGH-DOSE CHEMOTHERAPY: No contraindications to the stem cell collection by apheresis or by bone marrow harvesting * HIGH-DOSE CHEMOTHERAPY: All patients, or their legal guardians must have signed a voluntary informed consent in accordance with the institutional and federal guidelines * HIGH-DOSE CHEMOTHE…