Combination Chemotherapy With or Without Rituximab in Treating Older Patients With Non-Hodgkin's Lymphoma

OBJECTIVES: Primary * Compare the efficacy of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) with vs without rituximab in elderly patients with aggressive non-Hodgkin's lymphoma. * Compare the efficacy of 6 vs 8 courses of CHOP chemotherapy in patients treated with these regimens. * Compare the rate of complete remission, rate of primary progression, tumor control, disease-free survival, overall survival, and relapse after radiotherapy in patients treated with these regimens. * Compare the safety and side effects of these regimens in these patients. Secondary * Compare short-term and long-term side effects of these regimens in these patients. * Compare quality of life of patients treated with these regimens. * Compare the cost of these regimens in these patients. * Determine relapse in patients treated with these regimens who received involved-field radiotherapy. OUTLINE: This is a randomized (randomized part of study completed as of 6/2005), open-label, multicenter study. Patients are stratified according to participating center, value for serum lactic dehydrogenase (no greater than upper limit of normal \[ULN\] vs greater than ULN), bulky disease present (no vs yes), stage (I or II vs III or IV), general ECOG status of patient (0 or 1 vs 2), and age (61 to 70 vs 71-80). Patients are randomized to 1 of 4 treatment arms. Patients with CD20-negative lymphoma are randomized to arms I or II only. * Prephase treatment:Patients receive vincristine IV on day -6 and prednisone on day -6 to day 0 before initiating CHOP chemotherapy. * Arm I (closed to accrual as of 7/25/2005): Patients receive standard CHOP chemotherapy comprising cyclophosphamide IV, doxorubicin IV, and vincristine IV on day 1 and oral prednisone on days 1-5. Patients also receive filgrastim (G-CSF) subcutaneously once daily on days 6-12 of each CHOP course. Treatment repeats every 2 weeks for 6 courses. * Arm II (closed to accrual as of 7/25/2005): Patients receive standard CHOP chemotherapy and G-CSF as in arm I for a total of 8 courses. * Arm III: Patients receive standard CHOP chemotherapy and G-CSF as in arm I. Patients also receive rituximab IV before CHOP every 2 weeks for a total of 8 courses. * Arm IV (closed to accrual as of 7/25/2005): Patients receive standard CHOP chemotherapy and G-CSF as in arm II. Patients also receive rituximab IV before CHOP every 2 weeks for a total of 8 courses. In all arms, treatment continues in the absence of disease progression or unacceptable toxicity. Beginning 3-6 weeks after completion of the last chemotherapy course, after complete recovery of bone marrow, and after complete remision of mucositis, patients with sites of initial bulky disease or extranodal involvement undergo radiotherapy 5 times a week for 4 weeks. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter. PROJECTED ACCRUAL: Approximately 1580 patients will be accrued for this study within 5 years.