Abstract 2238: Clinical characteristics and outcome of patients with Rituximab-CHOP resistant/refractory DLBCL: Presence of B symptom and high LDH at diagnosis predict survival
Authors: Kim Min Kyoung , Koo Dong-Hoe , Suh Cheolwon , Yang Deok-Hwan , Kawk Jae-Yong , Lim Ho-Young , Oh Sung Yong , Moon Joon Ho , Lee Gyeong-Won , Bae Sung Hwa , Ryoo Hun Mo , Mun Yeungchul , Lee Kyung Hee , Hyun MyungSoo 
Published: June 2012

Abstract
Introduction: The addition of the anti-CD20 monoclonal antibody rituximab to conventional chemotherapy has dramatically improved overall survival (OS) in patients with diffuse large B-cell lymphoma (DLBCL), with more than 50% of these patients achieving long-term disease-free survival. However, approximately one-third of patients eventually die due to disease progression, treatment-related toxicities, another cancer, or other causes, and some patients show progression during or immediately after treatment. We sought to determine the characteristics of patients with DLBCL who were refractory or resistant to R-CHOP (rituximab, cyclophosphamide, adriamycin, vincristine, prednisone) chemotherapy and the factors influencing patient outcomes.
Patients and Methods: Of all patients newly diagnosed with DLBCL at nine institutions in Korea and treated with R-CHOP with curative intent, 94 failed to achieve complete (CR) or partial response (PR) during or after R-CHOP chemotherapy or showed disease progression within 12 months of diagnosis.
Results: Median patient age was 53 years (range 18∼85 years), and median time to progression was 5.7 months (range 1.1∼11.2 months). According to the International Prognostic Index (IPI), 44 patients (46.8%) were of low risk (0 to 2) and 50 (53.2%) were of high risk (3 to 5). Of the 94 patients, 59 (62.8%) had progression of primary lesions, 19 (20.2%) had progression at other sites, and 16 (17%) had progression at both primary and other sites. Sixty-three patients (67%) had progression during R-CHOP treatment, including 22 (23.4%) with progression after no response and 41 (43.6%) with progression after CR or PR. The remaining 31 patients (33.0%) showed disease progression after 6∼8 cycles of R-CHOP chemotherapy. Of the 74 patients (78.7%) who received second-line chemotherapy, 8 (10.8%) achieved CR or unconfirmed CR (CRu), 14 (18.9%) achieved PR, 3 (4.1%) achieved stable disease and 36 (48.6%) showed progressive disease. The overall response rate was 29.7% and the median duration of response was 4.2 months. Median OS was 4.7 months and median progression-free survival (PFS) was 3.0 months. Median OS after diagnosis of lymphoma was 10.7 months. Multivariate analysis showed that normal (vs. elevated) LDH concentration and absence (vs. presence) of B symptoms were significant predictors of longer OS. However, other IPI variables, such as age, performance status, and extranodal disease, did not predict survival of R-CHOP resistant/refractory patients.
Conclusion: The prognosis of patients with R-CHOP refractory/resistant DLBCL was dismal, with conventional salvage chemotherapy having little effect on survival. Novel biomarkers and new treatment strategies are needed to further improve survival in R-CHOP refractory/resistant DLBCL patients.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2238. doi:10.1158/1538-7445.AM2011-2238