Prognostic significance of serum beta-2 microglobulin in patients with non-Hodgkin lymphoma.

Elevated serum beta-2 microglobulin (β2-M) has previously been reported in non-Hodgkin lymphoma (NHL) patients. This study examined the association between serum β2-M and the prognosis of NHL and analyzed its predictive value. A total of 287 NHL patients from Taiyuan, Shanxi, China, participated in a prospective cohort study between 2008 and 2011. Overall survival (OS) was compared between NHL patients with high and normal β2-M levels using the log-rank test. Three standard Cox regression models including the International Prognostic Index (IPI) score, β2-M or IPI score+β2-M as independent variables were constructed. The time-dependent receiver operating characteristic curves method and C index were used to examine the tendency of the models' predictive accuracy over time. NHL patients with elevated β2-M values had worse OS (p<0.001) and higher mortality risk (HR=1.93, 95% CI 1.37-2.77, p<0.001) than patients with normal β2-M values. There were statistically significant differences between the C indexes for the models with IPI+β2-M, IPI or β2-M alone (p<0.001). Our results demonstrated an association between serum β2-M and NHL prognosis. Combining β2-M with IPI may help to improve the prognostic accuracy of NHL.