Bone Marrow Transplant Plus Cyclophosphamide and Total-Body Irradiation in Treating Patients With Hematologic Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage cancer cells. Combining chemotherapy and radiation therapy together with bone marrow transplant may allow the doctor to give higher doses of chemotherapy drugs and kill more cancer cells. PURPOSE: This phase II trial is studying how well giving bone marrow transplant from an unrelated donor together with cyclophosphamide and total-body irradiation works in treating patients with hematologic cancer.

OBJECTIVES: * Study the curative potential of high-dose cyclophosphamide and total-body irradiation followed by rescue with bone marrow from volunteer HLA-matched donors in patients with a variety of hematologic malignancies and bone marrow failure states. * Study the toxic effects associated with matched unrelated bone marrow transplantation in this patient population. * Participate in collaborative research studies with the National Marrow Donor Program. OUTLINE: All patients receive myeloablative therapy with high-dose cyclophosphamide and total body irradiation over 4 days; patients with severe aplastic anemia also receive antithymocyte globulin. Patients then undergo allogeneic bone marrow transplantation. Filgrastim (G-CSF) is given after transplant to accelerate engraftment. Sargramostim (GM-CSF) may be given in case of graft failure. All patients receive graft-versus-host-disease (GVHD) prophylaxis with tacrolimus, methotrexate, and gamma globulin. Established GVHD is treated with corticosteroids and, as necessary, antithymocyte globulin. Patients are followed at 100 days, 6 months, and 1 year after transplant, then annually thereafter. PROJECTED ACCRUAL: A total of 10 patients per year will be accrued for this study over 5 years.