 This study will evaluate the effectiveness of EPOCH-R chemotherapy plus bortezomib for treating mantle cell lymphoma, a cancer of white blood cells called lymphocytes. EPOCH-R consists of the drugs prednisone, etoposide, doxorubicin and vincristine, with the addition of a new drug called rituximab. In a recent study of patients with newly diagnosed mantle cell lymphoma, 92 percent had a complete remission of their disease after treatment with EPOCH-R. This study will test whether adding bortezomib as maintenance therapy once chemotherapy is finished will lengthen the time before the disease relapses and improve the overall cure rate. 