DISEASE CHARACTERISTICS: Previously untreated non-Hodgkin's lymphoma (NHL) of one of the following histologies: Diffuse large cell Follicular large non-cleaved cell Diffuse mixed cell Immunoblastic At least 2 of the following poor-prognosis factors required: Age over 60 Performance status greater than 1 Any elevation of LDH More than 1 extranodal site Ann Arbor stage III or IV T- and B-cell NHL eligible if meeting all above criteria No primary CNS lymphoma Brain involvement eligible if not primary