Prediction of Prognosis for Patients with Diffuse Large B-Cell Lymphoma Refractory to or in First Relapse After Initial R-CHOP Therapy: A Single-Institution Study.

Prognostic models for primary diffuse large B-cell lymphoma (DLBCL) resistant to or relapsing after initial therapy with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) have not been well-established. A refined categorization of normalized lactate dehydrogenase (LDH) (the ratio to the upper limit of normal) was recently shown to predict prognosis of newly-diagnosed patients with DLBCL better than mere dichotomization of LDH into 'normal' and 'abnormal' groups. To define the prognostic impact of the LDH ratio and various other factors in order to develop a new prognostic model system, we retrospectively analyzed 31 patients with refractory/relapsed DLBCL initially treated with R-CHOP at our hospital from 2002 to 2013. Median age at the start of salvage therapy was 63 years. Median time from diagnosis to relapse was 349 days. In univariate analysis, LDH, short time from initial diagnosis to relapse (TTR), and low absolute lymphocyte count at relapse (ALC-R) were significant factors for reduced progression-free survival, and the LDH ratio was a more powerful factor than LDH abnormality. Furthermore, an LDH ratio >3 and short TTR were independent prognostic factors in multivariate analysis. We built a new prognostic scoring system, namely the time, LDH, and lymphocyte count (TLL), based on TTR, LDH ratio, and ALC-R, which is able to separate patients into three risk groups with 2-year PFS of 100%, 68.6% and 4.8%, respectively, and which also predicts outcome of autologous stem cell transplantation at the start of salvage therapy. The present study indicates that the LDH ratio is an important predictor of survival for patients with refractory/relapsed DLBCL and proposes the TLL index as a useful prognostic tool.