Long-term prognostic value of serum beta 2 microglobulin in myelomatosis.

The prognostic value of serum beta 2 microglobulin (s beta 2m) measured at entry, at plateau and at 3-monthly follow-up times has been assessed for patients in the Medical Research Council's 4th and 5th Myelomatosis Trials. Analysis of 1014 patients confirmed the value of presentation s beta 2m of predicting survival in the short term but showed that predictive value was lost for subsequent survival in those patients who had survived for at least 2 years. However, measurements of s beta 2m taken during follow-up were predictive of subsequent survival. The predictive power of these follow-up measurements was very similar to that for the presenting measurement, and again they were only of value in predicting survival in the next 2 years.