Multiple myeloma.

Multiple myeloma (MM) constitutes 1% of malignant diseases and 15% of haematological malignancies. In virtually all patients MM is preceded by monoclonal gammopathy of undetermined significance (MGUS). The cause of monoclonal gammopathies and the mechanisms of progression are unknown. The diagnosis of MM requires the presence of an M-protein in serum and/or urine, increased bone marrow plasma cells and related organ or tissue impairment. Cytogenetic status, serum β2-microglobulin and response to therapy are the key prognostic factors. The treatment of younger patients with MM should include a triple-agent induction regimen (i.e. bortezomib/thalidomide/dexamethasone), autologous stem cell transplantation (ASCT) and consolidation and maintenance incorporating novel agents along with sequential minimal residual disease studies to determine for how long treatment is still of benefit. Allogeneic transplantation with reduced-intensity conditioning is promising but remains experimental. For patients not eligible for ASCT the best initial regimens are melphalan/prednisone/thalidomide (MPT), melphalan/prednisone/bortezomib (MPV) and lenalidomide/dexamethasone. In relapsing patients, the choice of salvage therapy should depend on: (i) the components of initial therapy, (ii) the degree and duration of response, (iii) type of relapse: aggressive versus indolent, (iv) previous toxicities and (v) age and performance status. A sequential approach is preferred over combination of multiple agents. Supportive measures include the use of bisphosphonates and erythropoietin according to the updated guidelines.