Effect of M-protein secretory status on PFS and OS of patients with MM receiving thalidomide- or bortezomib-based therapy. The median PFS and OS of MM patients was significantly longer in patients with measurable disease than in those with oligosecretory, nonsecretory, and nonproducer MM regardless of thalidomide- (A-B) or bortezomib-based (C-D) therapy. Within the unmeasurable group, patients with nonproducer myeloma showed the shortest PFS and OS.