High-risk multiple myeloma: different definitions, different outcomes?

Multiple myeloma (MM) is a clonal plasma cell malignancy. Although MM is still not completely curable, it can be maintained at the level of a long-term chronic condition. Irrespective of the treatment strategy, relapse is still a major problem for most patients. Approximately 10% to 15% of all MM patients relapse early and have poor prognosis and outcome. Currently, there are many ways of identifying these high-risk patients using cytogenetics or molecular biology. Despite these various approaches to definition of high risk patients, a clear definition of high-risk MM has not been widely accepted. In this review, we discuss and compare various approaches, and their strengths and weaknesses in early identification of high-risk MM patients.