Risk stratification based on bone marrow plasmacytosis, serum M protein, and serum immunoglobulin FLC ratio. Patients are assigned 1 point for meeting each of the following criteria: BMPCs greater than or equal to 10%; serum M protein greater than or equal to 3 g/dL; and serum immunoglobulin FLC ratio either less than 0.125 or more than 8. The median times to progression for 1, 2, or 3 risk factors are 10, 5.1, and 1.9 years, respectively.