Myeloma today: Disease definitions and treatment advances

There have been major advances in the diagnosis, staging, risk-stratification, and management of multiple myeloma (MM). In addition to established CRAB (hypercalcemia, renal failure, anemia, and lytic bone lesions) features, new diagnostic criteria include three new biomarkers to diagnose the disease: bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain ratio ≥100, and >1 focal lesion on magnetic resonance imaging. MM can be classified into several subtypes based on baseline cytogenetics, and prognosis varies according to underlying cytogenetic abnormalities. A Revised International Staging System has been developed which combines markers of tumor burden (albumin, beta-2 microglobulin) with markers of aggressive disease biology (high-risk cytogenetics and elevated serum lactate dehydrogenase). Although the approach to therapy remains largely the same, the treatment options at every stage of the disease have changed. Carfilzomib, pomalidomide, panobinostat, daratumumab, elotuzumab, and ixazomib have been approved for the treatment of the disease. These drugs combined with older agents such as cyclophosphamide, dexamethasone, thalidomide, bortezomib, and lenalidomide dramatically increase the repertoire of regimens available for the treatment of MM. This review provides a concise overview of recent advances in MM, including updates to diagnostic criteria, staging, risk-stratification, and management.