[Smoldering multiple myeloma]

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell neoplasia, characterized by monoclonal plasma cell proliferation in the absence of end-organ damage, but with a high risk of progression to multiple myeloma. It has therefore to be distinguished from monoclonal gammapathy of undetermined significance (MGUS), which has a much lower risk of progression, but also from multiple myeloma, which remains an incurable disease and requires a specific treatment. The critical question in the management of SMM is whether an early therapeutic strategy could help delaying the progression to multiple myeloma, in order to lower the risk of serious complications related to this progression, or even to cure the disease. This early treatment could not be proposed to all SMM patients, who are indeed asymptomatic, and in whom the risk of toxicity could make it difficult to justify the potential benefit obtained. The challenge is to target early at diagnosis SMM patients with a high risk of progression, using available routine tests sufficiently reliable to warrant the therapeutic sanction which relies on it. Today however, apart from randomized studies, recommendations are to maintain therapeutic abstention in SMM patients.