[The epidemiology of multiple myeloma].

We investigated epidemiology of multiple myeloma (MM), referring to recent papers. This article includes three points: 1) the progression rate of monoclonal gammopathy of undetermined significance (MGUS) to MM, 2) the effect of radiation to prevalence of MM, and 3) secondary malignancy after chemotherapy used to treat MM. The risk of progression from MGUS to MM is 1% per year. The researches of atomic bomb showed that there is no increase of risk of MM after radiation exposure. In contrast, studies investigating workers in nuclear power plants point out that radiation exposure over 50 mSv increases risk of MM. The incidence of secondary malignancy after chemotherapy used to treat MM was about 5%. This article will help to review recent researches about epidemiology of MM.