High-Dose Busulfan and High-Dose Cyclophosphamide Followed By Donor Bone Marrow Transplant in Treating Patients With Leukemia, Myelodysplastic Syndrome, Multiple Myeloma, or Recurrent Hodgkin or Non-Hodgkin Lymphoma

RATIONALE: Giving high doses of chemotherapy drugs, such as busulfan and cyclophosphamide, before a donor bone marrow transplant helps stop the growth of cancer cells. It may also stop the patient’s immune system from rejecting the donor’s stem cells. When the healthy stem cells from a donor are infused into the patient they may help the patient’s bone marrow make stem cells, red blood cells, white blood cells, and platelets. Sometimes the transplanted cells from a donor can make an immune response against the body’s normal cells. Giving cyclosporine, methylprednisolone, and methotrexate after transplant may stop this from happening.
PURPOSE: This clinical trial studies high-dose busulfan and high-dose cyclophosphamide followed by donor bone marrow transplant in treating patients with leukemia, myelodysplastic syndrome, multiple myeloma, or recurrent Hodgkin or Non-Hodgkin lymphoma.