RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Bone marrow transplantation may allow doctors to give higher doses of chemotherapy drugs and kill more cancer cells. It is not yet known whether high dose chemotherapy plus bone marrow transplantation is more effective than high dose chemotherapy alone for intermediate- or high-grade non-Hodgkin's lymphoma.

PURPOSE: Randomized phase III trial to compare the effectiveness of high dose chemotherapy with or without bone marrow transplantation in treating patients who have intermediate- or high-grade non-Hodgkin's lymphoma.

OBJECTIVES: I. Assess the value of early intensification with autologous bone marrow transplantation or stem cell support in patients with poor prognosis intermediate or high grade non-Hodgkin's lymphoma.

OUTLINE: This is a randomized, multicenter study. Patients are stratified by age (under 50 vs 50 and over), bone marrow involvement (yes vs no), and country. All patients receive cyclophosphamide, doxorubicin, and vincristine on day 1 and prednisone on days 1-5. Courses repeat every 21 days. Patients receive a minimum of 6 courses of treatment in the absence of disease progression and unacceptable toxicity. Arm I: Patients receive carmustine IV over 2 hours on day 1 in week 9 or 10. Etoposide and cytarabine IV are administered over 30 minutes on days 2-5. Melphalan IV is administered over 5 minutes on day 6. Patients receive cryopreserved bone marrow or peripheral blood stem cells on day 7. Arm II: Patients continue conventional therapy. Patients are followed at 8-9 weeks and 6 months.

PROJECTED ACCRUAL: This study will accrue 500 patients.

DISEASE CHARACTERISTICS: Histologically confirmed intermediate or high grade adult non-Hodgkin's lymphoma: Follicular large cell lymphoma Diffuse mixed cell lymphoma Diffuse large cell lymphoma Diffuse immunoblastic lymphoma Poor prognostic features defined as the presence of 2 or 3 of the following: Stage III/IV Lactase dehydrogenase greater than normal ECOG performance status 2-4 A new classification scheme for adult non-Hodgkin's lymphoma has been adopted by PDQ. The terminology of "indolent" or "aggressive" lymphoma will replace the former terminology of "low", "intermediate", or "high" grade lymphoma. However, this protocol uses the former terminology.

PATIENT CHARACTERISTICS: Age: 16 to 65 Performance status: See Disease Characteristics Life expectancy: Not specified Hematopoietic: Not specified Hepatic: See Disease Characteristics Renal: Not specified Other: No other medical condition prohibiting intensive therapy

PRIOR CONCURRENT THERAPY: At least 5 years since prior systemic therapy for cancer