Patients receive carmustine IV over 2 hours on day -6; etoposide IV over 3 hours and cytarabine IV over 1 hour every 12 hours on days -5 to -2 for a total of 8 doses; and melphalan IV over 20-30 minutes on day -1. Patients undergo allogeneic peripheral blood stem cell (PBSC) transplantation on day 0. Patients also receive tacrolimus IV continuously over 24 hours beginning on day -2 and then orally twice daily until day 120 and methotrexate IV over 30 minutes on days 1, 3, and 6 as graft-versus-host disease (GVHD) prophylaxis. Patients receive sargramostim (GM-CSF) IV or subcutaneously daily beginning on day 7 and continuing until blood counts recover.