Age, gender, race, radiation exposure, family history, occupational exposure, obesity, and other plasma cell diseases are some of the risk factors of myeloma. Unfortunately each risk isn't talked about in depth.

This website holds a lot of information about myeloma and MGUS, which is very well explained. It is well-worth reading although myeloma is a relatively rare cancer, knowledge of the risk-factors is usefull although little is known about them