The lymphocyte to monocyte ratio improves the IPI-risk definition of diffuse large B-cell lymphoma when rituximab is added to chemotherapy

The peripheral blood lymphocyte to monocyte ratio (LMR) at diagnosis can be clinically relevant in patients with diffuse large B-cell lymphoma (DLBCL). We reviewed the outcome of 1,057 DLBCL patients followed from 1984 to 2012 at four centers. LMR was analyzed as a clinical biomarker by receiver-operating characteristic (ROC) analysis and Harrell's C-statistics. Patients were characterized by a median age of 61 years, International Prognostic Index (IPI) score of >2 in 39%, and were treated with a rituximab-containing chemotherapy in 66%. LMR proved strongly predictive for survival in patients treated with rituximab-based programs, but not in those receiving chemotherapy alone. Additionally, an LMR value of 642.6 (as determined by ROC analysis) was associated with a worst performance status, a higher lactate dehydrogenase (LDH) level, an advanced clinical stage, and a higher IPI score (P=0.000). In patients treated with rituximab-supplemented chemotherapy programs, an LMR value of