Beta-2 microglobulin is a strong prognostic factor in patients with DLBCL receiving R-CHOP therapy

Useful prognostic markers for patients with diffuse large B cell lymphoma (DLBCL) have been reported. To identify which biomarker best predicts the prognosis of patients with DLBCL, we performed a retrospective study that included 319 DLBCL patients who had received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy between 2003 and 2012. We assessed the prognostic significance of six biomarkers [lactate dehydrogenase, soluble interleukin-2 receptor, thymidine kinase activity, beta-2 microglobulin (B2M), C-reactive protein, and ferritin] and representative clinical characteristics using progression-free survival (PFS) as the endpoint. The study group included 181 men and 138 women with a median age of 63 years (range, 22-89 years). In a multivariate analysis, the serum B2M level most strongly correlated with PFS (hazard ratio, 2.11; P=0.04). In a univariate analysis, patients with serum B2M levels >1.75μg/mL (n=210) had a worse 3-year PFS rate (71.2%) than those with B2M levels <1.75μg/mL (n=109; 90.0%). Therefore, serum B2M level at the time of diagnosis is a useful prognostic indicator in DLBCL patients receiving R-CHOP.