International Staging System (ISS) for Symptomatic Myeloma

Prognostic score for newly-diagnosed symptomatic myeloma

ISS stage1CriteriaFive year OS2
Iβ2-microglobulin < 3.5 mg/L (< 296 nmol/L) AND albumin ≥ 35 g/L66
IINot meeting criteria for stage I or III45
IIIβ2-microglobulin > 5.5 mg/L18
Data from Greipp et al, 20051 and Kastritis et al, 2009.2

The International Staging System (ISS) derives from multivariate analysis of survival of > 10,000 patients with newly-diagnosed symptomatic myeloma.1 Initial treatment was administered between 1981 and 2002, and included autologous stem cell transplantation in a quarter of patients.

The ISS stage retains prognostic relevance in the era of novel agents (thalidomide, bortezomib, lenalidomide): Five year overall survival among patients who received first line therapy including novel agents was 66%, 45% and 18% for ISS stage I, II and III patients, respectively.2