Hindawi Publishing Corporation ISRN Hematology Volume 2013, Article ID 908191, 9 pages http://dx.doi.org/10.1155/2013/908191 Research Article Detailed Analysis of Diffuse Large B Cell Lymphoma Patients: A Single-Center, Retrospective Study Murat Ozbalak, 1 M. Cem Ar, 1 Nukhet Tuzuner, 2 Ayse Salihoglu, 1 A. Emre Eskazan, 1 Seniz Ongoren Aydin, 1 Zafer Baslar, 1 Teoman Soysal, 1 Yildiz Aydin, 1 Anil Barak Dolgun, 3 Onder Ergonul, 4 and Burhan Ferhanoglu 1 1 Division of Haematology, Department of Internal Medicine, Istanbul University, Cerrahpasa Medical Faculty, Cerrahpasa Cd., No. 181, Kocamustafapasa-Fatih, 34098 Istanbul, Turkey 2 Division of Haematopathology, Department of Pathology, Istanbul University, Cerrahpasa Medical Faculty, Istanbul, Turkey 3 Department of Biostatistics, Hacettepe University Medical Faculty, Ankara, Turkey 4 Department of Infectious Diseases, Koc ¸ University Medical School, Istanbul, Turkey Correspondence should be addressed to Burhan Ferhanoglu; bferhan@superonline.com Received 5 June 2013; Accepted 9 July 2013 Academic Editors: L. Bordin, A. Bosly, D. Del Principe, K. Oritani, and F. W. Quelle Copyright © 2013 Murat Ozbalak et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te aim of this single-center, retrospective study was to investigate the impact of rituximab, reconsider the validity of International Prognostic Index (IPI), and evaluate the prognostic role of the cell of origin (CoO) in a relatively young cohort. Tree hundred twelve difuse large B cell lymphoma patients (median age: 52) were included. Rituximab signifcantly improved the 3- and 5-year progression free survival (PFS) (70% versus 65% and 41% versus 36%, resp.;  < 0.001) but led only to a slight, insignifcant increase in 3- and 5-year overall survival (OS) (71% versus 77.3% and %67 versus 74.5%, resp.;  = 0.264). In the young, low risk patient subgroup (aaIPI = 0&1;  = 129), rituximab improved 3- and 5-year PFS and OS rates ( < 0.001 and  = 0.048, resp.). Te efcacy of rituximab in young high risk patients was comparable to the literature. CoO data were available in 190 patients. Te OS at 3 years was 79% for GC and 64% for non-GC subgroups ( = 0.014). To the best of our knowledge, this is the frst study which investigated the impact of R-CHOP in the context of CoO and IPI in a relatively young cohort. CoO was not an independent risk factor for prognosis in the multivariate analysis although patients with GC showed a signifcant survival advantage in the univariate analysis. CoO was also found to be a signifcant determinant of response in refractory/relapsed patients. Our results confrm the efcacy of rituximab in low and high risk, young patients outside of a randomized clinical trial setting. 1. Introduction Difuse large B cell lymphoma (DLBCL), being the most common morphological type, constitutes about 40% of newly diagnosed non-Hodgkin’s lymphoma (NHL) cases. It is a heterogeneous disease with variable clinical course and prog- nostic outcome. Addition of the immunotherapeutic agent rituximab to chemotherapy improved the response rates in NHL [1]. However, despite major progress in the treatment, responses are not durable and the outcome is fatal in almost half of the patients with DLBCL. Terefore, great interest has been shown to develop prognostic scoring systems that would predict the outcome and identify patients with worst prognosis who would beneft from treatment strategies other than the standard regimens. Until recently, International Prognostic Index (IPI) [2] was almost the only widely used prognostic indicator in DLBCL. However, increasing evidence suggest that IPI fails to predict the prognosis in a considerable portion of patients with DLBCL. Consequently, there is a need for an improved and/or refned prognostic index which would predict the outcome more precisely. In search for such an index, various immunohistochemical markers have been investigated in DLBCL. Gene expression profling studies identifed three prognostically signifcant groups defned as “germinal center B cell (GCB),” “activated B cell,” and “primary mediastinal