 All patients consenting to enter the main study will be given an initial cycle of RCHOP chemotherapy. Within each subgroup ABC or GCB patients will be randomly assigned to receive either RCHOP or RCHOP and bortezomib to ensure that the same number of each biological subgroup will receive the two treatments. All patients will then have 5 cycles of their assigned treatment regimen either RCHOP or RCHOP and bortezomib. All patients will be followed up for a period of five years once they have completed their chemotherapy. The GCB group receiving RCHOP and bortezomib will be regularly checked to see if the new treatment is improving survival without recurrence of the disease. If the addition of bortezomib is not found to be beneficial for this group of patients this part of the trial will be stopped and all GCB patients will receive the standard treatment only RCHOP. 