HDT indicates high-dose therapy; VDL-PACE, bortezomib, dexamethasone, lenalidomide, cisplatin, adriamycin, cyclophosphamide, etoposide; DCEP, dexamethasone, cyclophosphamide, etoposide, cisplatin; and RIC-Alo-SCT: reduced-intensity conditioning regimen followed by alllogeneic SCT.