 - Part 2: EPOCH-R chemotherapy plus bortezomib: This phase of treatment begins 3 to 4 weeks after completing Part 1. Treatment is given on an outpatient basis in six 3-week cycles, with all drugs administered over the first 5 days of each cycle. Patients take prednisone by mouth on days 1 to 5 and etoposide, doxorubicin, and vincristine as a 96-hour infusion through a vein over days 1 to 5. The infused drugs are delivered through a lightweight, portable infusion pump. Rituximab is given by vein over several hours on day 1 immediately before the chemotherapy infusion begins. Bortezomib is given by vein over 30 seconds on day 1 before the rituximab and again on day 4. Cyclophosphamide is given by vein over about 15 minutes on day 5 immediately after the chemotherapy infusion is completed. Patients are taught how to self inject G-CSF, a drug that helps boost white cell counts after chemotherapy. They inject the drug under the skin like an insulin shot for 10 days of each cycle beginning day 6. Patients also take an antibiotic to help prevent infection during chemotherapy. 