DA-EDOCH14-R in Poor-prognosis Diffuse Large B-cell Lymphoma

Medication, Dose and Method for Administration: * Rituximab: 375 mg/m2, endovenous, according to the protocol of the service, day 1 (except in the first cycle, in which it will be on day 5). * Etoposide: 50 mg/m2/day, in continuous 24-hour infusion, days 1 to 4. * Adriamycin: 10 mg/m2/day, in continuous 24-hour infusion of, days 1 to 4. * Vincristine: 0.4 mg/m2/day, in continuous 24-hour infusion, days 1 to 4 * Dexamethasone: 40 mg, endovenous, days 1 to 5. Followed by prednisone 30 mg (day +6), 20 mg (day +7), and 10 mg (day +8). * Cyclophosphamide: 750 mg/m2, endovenous, in 30 minutes, day 5, after ending the continuous infusion of adriamycin, etoposide and vincristine. * MESNA (If the dose of Cyclophosphamide is \> 1 g/m2