Evaluation of Clinical and Biological Prognostic Factors in Relapsed or Refractory Diffuse Large B-Cell Lymphoma Patients After Previous Treatment With Rituximab and Chemotherapy: Results of the PRO-R-IPI Study

Resumen:
We aimed to evaluate the revised International Prognostic Index (R-IPI) to predict the outcome of relapsed/refractory diffuse large B-cell lymphoma patients and try to establish the relationship between biological parameters and outcome. Neither R-IPI at diagnosis or relapse nor the immunohistochemical parameters evaluated identified, risk groups with different overall response rates. Only absolute lymphocyte count identified patients who were less likely to achieve an overall response. This highlights the significance of host immunity in determining clinical outcomes in non-Hodgkin lymphoma. Introduction: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity, showing a highly variable outcome. In patients with DLBCL relapsed/refractory to first-line treatment with rituximab the usefulness of the revised International Prognostic Index (R-IPI) as a prognostic tool remains unexplored. Some biological parameters (B-cell lymphoma 6 [Bcl-6], Bcl-2, p53, and multiple nnyeloma 1 [MUM1]) and blood populations (lymphocyte and monocyte counts) have been described as International Prognostic Index-independent prognostic factors. The objective was to evaluate the R-IPI to predict the outcome of DLBCL patients at the time of relapse after a front-line treatment with chemotherapy and rituximab and to establish in this population the relationship between biological parameters and outcome. Patients and Methods: We included patients with refractory/relapsed DLBCL after first-line treatment with rituximab-containing regimens; patients must have already finished a rescue treatment also including rituximab. Immunohistochemical assessment of Bcl-2, Bcl-6, p53, and MUM1 expression were undertaken in available biopsies. R-IPI factors were identified from the clinical data at diagnosis and at relapse. Response was assessed using National I Cancer Institute-sponsored Working Group guidelines. Results: R-IPI prognosis at relapse was not significantly associated with overall response rate (ORR) after Rituximab-chemotherapy rescue therapy. None of the immunohistochemical parameters analyzed correlated with rescue therapy results. In contrast, patients with absolute lymphocyte count (ALC) >= 1 x 10(9)/L at relapse were more likely to respond than patients with ALC < 1 x 10(9)/L (P = .05). Conclusion: The R-IPI score calculated at relapse could not predict the ORR to second-line treatment. Lymphopenia is a simple and useful predictor for outcome in relapsed/refractory DLBCL and the only prognostic factor that in our hands could predict the overall response to a second-line treatment with rituximab and chemotherapy. (C) 2015 Elsevier Inc. All rights reserved.