Fifteen to forty per cent of multiple myeloma patients have renal impairment at diagnosis. The Durie-Salmon staging included renal impairment as an adverse prognostic factor and so does the International Staging System, since β2-microglobulin correlates with both tumour burden and renal impairment. However, the introduction of new therapeutic agents (as bortezomib, lenalidomide, and thalidomide) and new prognos...