Clinical staging in multiple myeloma.

Analysis of 237 patients with myeloma, retrospectively classified according to the staging system proposed by Durie and Salmon, showed highly significant differences (P less than 0.0001) in the survival of patients with low, intermediate and high tumour cell masses (Stages I, II and III respectively). The median survival for Stage I patients was 64 months, Stage II 32 months, and Stage III 6 months. The median survival of patients presenting with renal impairment was only 2 months, compared to 21 months for those presenting with normal renal function (P less than 0.0001). The use of this clinical staging system, which is based on myeloma protein synthesis rates and the calculation of total body tumour cell mass, should be considered in planning future trials of therapy in this disease.