I. Compare, in a randomized setting, the time to treatment failure and the survival of patients with poor-prognosis intermediate-grade or immunoblastic lymphoma treated with the standard regimen of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) versus the new alternating triple therapy (ATT) of IdSHAP (idarubicin, cisplatin, cytarabine, methylprednisolone), BIdCOS (idarubicin, vincristine, bleomycin, cyclophosphamide, methylprednisolone), and MINE (mesna, ifosfamide, mitoxantrone, etoposide).