Performance of newer myeloma staging systems in a contemporary, large patient cohort

The most widely used staging system for patients with multiple myeloma (MM), the Revised International Staging System (R-ISS), is based on beta-2 microglobulin (B2M), albumin, lactate dehydrogenase (LDH), and the presence of high-risk cytogenetics [ 1 ]. However, it does not account for the additive risk imposed by multiple cytogenetic abnormalities or the presence of copy number gains at chromosome 1q21 (gain1q) [ 2 ]. The majority of patients (62%) are staged as R-ISS Stage II, with marked variation in prognosis depending on the co-occurrence of specific cytogenetic abnormalities [ 1 , 3 ].