Comparison of HD Chemotherapy Followed by Auto-transplant and R-CHOP in High Risk Patients With DLBCL.

Inclusion Criteria: * Diagnosis of DLBCL CD20+. * Patients with Ann Arbor classification B-bulk \>= II * Patients of age between 18-65 with age-adjusted IPI 2-3 and ECOG performance status 0-3 or patients of age 61-65 with IPI 3, 4, 5 and ECOG performance status 0-2. The disease stage criteria must be documented with instrumental examinations and bone marrow biopsy. * Hematology parameters one week before starting study as follows: Hb \>= 9 g/dl, WBC \>= 3 x 10exp9/l, neutrophils \>= 1.5 x 10exp9/l, PLT \>= 100 x 10exp9/l. * Patients with pulmonary DLCO \>= 50% and cardiac EF \>= 40%. * Voluntary written informed consent must be signed before recruitment, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care. Patients must to be informed on the risk of sterility and they must agree to use contraception for the duration of the study. Male subject have to the opportunity of freezing seminal fluid. Exclusion Criteria: * Diagnosis different from that describe above. * Patients with concomitant, serious and uncontrolled illnesses such as cardiopathies (i.e. congestive cardiopathy, ischemic hearth disease, cardiac arrhythmia not controlled by therapy, IMA in the last six months, hearth disease NYHA class III or IV), hepatopathy not related to the lymphoma (bilirubin \>= 2 mg/dl, ALT \>= 2.5 times the normal value, alkaline phosphatase \>=2.5 times the upper limit), kidneys insufficiency not related to the lymphoma (creatinine \>=2 mg/dl). * Patients affected by opportunistic infections or with positive serology for HIV, HCV, HbsAg (cases with normal levels of hepatic enzymes and not showing active viral replication documented with HBV-DNA are not excluded from randomization; patients with HBV+ can be enrolled after receiving prophylaxis with lamivudina one week before starting chemotherapy. These patients should be monitored twice a month for HbsAg, HBCab, HBV-DNA). * Patients which have or have had another type of cancer exception made for skin cancers (melanoma and "in situ" cervical cancer not included). * Patient with a history of anaphylaxes or more generally patients which have had any serious allergic reaction after serum infusion. * Patient with uncontrolled epilepsy, CNS disorders or psychiatric problems which, according to the investigator, is likely to interfere with participation in this clinical study (i.e. the signing of the informed consent, therapy compliance). * Inability to attend follow-up visits.