Purpose: There is a need for a simple, reliable staging system for multiple myeloma that can be applied internationally for patient classification and stratification.Patients and Methods: Clinical and laboratory data were gathered on 10,750 previously untreated symptomatic myeloma patients from 17 institutions, including sites in North America, Europe, and Asia. Potential prognostic factors were evaluated by univariate and multivariate techniques. Three modeling approaches were then explored to develop a staging system including two nontree and one tree survival assessment methodologies.Results: Serum beta₂-microglobulin (Sβ₂M), serum albumin, platelet count, serum creatinine, and age emerged as powerful predictors of survival and were then used in the tree analysis approach. A combination of Sβ₂M and serum albumin provided the simplest, most powerful and reproducible three-stage classification. This new International Staging System (ISS) was validated in the remaining patients and consists of the following stages: stage I, Sβ₂M less than 3.5 mg/L plus serum albumin ≥ 3.5 g/dL (median survival, 62 months); stage II, neither stage I nor III (median survival, 44 months); and stage III, Sβ₂M ≥ 5.5 mg/L (median survival, 29 months). The ISS system was further validated by demonstrating effectiveness in patients in North America, Europe, and Asia; in patients less than and ≥ 65 years of age; in patients with standard therapy or autotransplantation; and in comparison with the Durie/Salmon staging system.Conclusion: The new ISS is simple, based on easy to use variables (Sβ₂M and serum albumin), and recommended for early adoption and widespread use.

Purpose: The clinical outcome of multiple myeloma (MM) is heterogeneous. A simple and reliable tool is needed to stratify patients with MM. We combined the International Staging System (ISS) with chromosomal abnormalities (CA) detected by interphase fluorescent in situ hybridization after CD138 plasma cell purification and serum lactate dehydrogenase (LDH) to evaluate their prognostic value in newly diagnosed MM (NDMM).Patients and Methods: Clinical and laboratory data from 4,445 patients with NDMM enrolled onto 11 international trials were pooled together. The K-adaptive partitioning algorithm was used to define the most appropriate subgroups with homogeneous survival.Results: ISS, CA, and LDH data were simultaneously available in 3,060 of 4,445 patients. We defined the following three groups: revised ISS (R-ISS) I (n = 871), including ISS stage I (serum β₂-microglobulin level < 3.5 mg/L and serum albumin level ≥ 3.5 g/dL), no high-risk CA [del(17p) and/or t(4;14) and/or t(14;16)], and normal LDH level (less than the upper limit of normal range); R-ISS III (n = 295), including ISS stage III (serum β₂-microglobulin level > 5.5 mg/L) and high-risk CA or high LDH level; and R-ISS II (n = 1,894), including all the other possible combinations. At a median follow-up of 46 months, the 5-year OS rate was 82% in the R-ISS I, 62% in the R-ISS II, and 40% in the R-ISS III groups; the 5-year PFS rates were 55%, 36%, and 24%, respectively.Conclusion: The R-ISS is a simple and powerful prognostic staging system, and we recommend its use in future clinical studies to stratify patients with NDMM effectively with respect to the relative risk to their survival.

High-dose therapy with supporting autologous stem-cell transplantation remains a controversial treatment for cancer. In multiple myeloma, first-line regimens incorporating high-dose therapy yield higher remission rates than do conventional-dose treatments, but evidence that this translates into improved survival is limited. In this multicenter study, the Medical Research Council Myeloma VII Trial, we randomly assigned 407 patients with previously untreated multiple myeloma who were younger than 65 years of age to receive either standard conventional-dose combination chemotherapy or high-dose therapy and an autologous stem-cell transplant. Among the 401 patients who could be evaluated, the rates of complete response were higher in the intensive-therapy group than in the standard-therapy group (44 percent vs. 8 percent, P<0.001). The rates of partial response were similar (42 percent and 40 percent, respectively; P=0.72), and the rates of minimal response were lower in the intensive-therapy group than in the standard-therapy group (3 percent vs. 18 percent, P<0.001). Intention-to-treat analysis showed a higher rate of overall survival (P=0.04 by the log-rank test) and progression-free survival (P<0.001) in the intensive-therapy group than in the standard-therapy group. As compared with standard therapy, intensive treatment increased median survival by almost 1 year (54.1 months [95 percent confidence interval, 44.9 to 65.2] vs. 42.3 months [95 percent confidence interval, 33.1 to 51.6]). There was a trend toward a greater survival benefit in the group of patients with a poor prognosis, as defined by a high beta₂-microglobulin level (more than 8 mg per liter). High-dose therapy with autologous stem-cell rescue is an effective first-line treatment for patients with multiple myeloma who are younger than 65 years of age.