Multiple myeloma is a cancer that develops in the bone marrow, the spongy tissue found in the center of most bones. Multiple myeloma is characterized by abnormalities in plasma cells, a type of white blood cell. These abnormal cells multiply out of control, increasing from about one percent of cells in the bone marrow to the majority of bone marrow cells. The abnormal cells form tumors within the bone, causing bone pain and an increased risk of fractures.
Relapsed Myeloma refers to when a patient had active treatment, went off treatment and then the disease came back.
Refractory Myeloma refers to as disease that is progressing despite active treatment.