Study Of Two Non-Myeloablative Stem Cell Transplant Strategies For Low-Grade Lymphoma And CLL

OBJECTIVES: * Compare the 1-year overall survival rate of patients with relapsed low-grade non-Hodgkin's lymphoma or chronic lymphocytic leukemia treated with fludarabine and total body irradiation vs cyclophosphamide and fludarabine followed by allogeneic peripheral blood stem cell transplantation and donor lymphocyte infusions. * Compare the toxic effects of these regimens in these patients. * Compare the incidence and severity of acute and chronic graft-versus-host disease in patients treated with these regimens. * Compare the 1-year treatment-related mortality and infectious complications in patients treated with these regimens. * Compare the efficacy of these treatment regimens, in terms of 1-year disease-free survival, of these patients. * Compare the quality of life of patients treated with these regimens. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to disease, age (less than 55 vs over 55), and participating transplantation center. Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive fludarabine IV on days -4 to -2. Patients undergo total body irradiation followed by allogeneic peripheral blood stem cell transplantation (PBSCT) on day 0. Patients receive graft-versus-host disease (GVHD) prophylaxis comprising oral cyclosporine twice daily on days -2 to 90 followed by a taper on days 90-150 and oral mycophenolate mofetil twice daily on days 0-28. * Arm II: Patients receive fludarabine IV on days -6 to -2 and cyclophosphamide IV on days -3 to -2. Patients undergo PBSCT on day 0. Patients receive GVHD prophylaxis comprising methotrexate IV on days 1, 3, 6, and 11 and tacrolimus IV continuously and then orally on days -2 to 90 followed by a taper on days 90-150. At approximately day 180, patients with persistent disease, evidence of T-cell chimerism, and no GVHD may receive up to 3 donor lymphocyte infusions administered every 1-2 months. Quality of life is assessed at baseline, 1 month, every 3 months for 1 year, and then every 6 months for 1 year. Patients are followed at 1 month, every 3 months for 1 year, and then annually for 2 years. PROJECTED ACCRUAL: A total of 100 patients (50 per treatment arm) will be accrued for this study.