IMWG Revises International Staging System for Multiple Myeloma

The revised International Staging System (ISS) is a new risk stratification algorithm with improved prognostic power compared with the individual ISS, chromosomal abnormalities, and serum lactate dehydrogenase parameters in patients with newly diagnosed multiple myeloma, according to a report from the International Myeloma Working Group (IMWG) published online ahead of print in the Journal of Clinical Oncology.¹

The American Cancer Society estimates that nearly 27,000 Americans will be diagnosed with multiple myeloma in 2015 and approximately 11,240 patients will die from the disease.²

Previously, the ISS, which was published in 2005, was a simple risk stratification system that was only based on serum β₂-microglobulin level and serum albumin level, but chromosomal abnormalities and serum lactate deydrogenase level are key elements to characterize biologic features of multiple myeloma.¹

“The revision was required to integrate both ISS, chromosomal abnormalities, and LDH,” Antonio Palumbo, MD, lead author and Chief of the Myeloma Unit at the University of Torino in Italy said in an interview with Cancer Therapy Advisor.

For the study, researchers from the IMWG analyzed clinical and laboratory data from 4,445 patients with newly diagnosed multiple myeloma who participated in 11 international trials. Of those, ISS, chromosomal abnormalities, and serum lactate dehydrogenase data were available in 3,060 patients.¹