ONCOLOGY Vol 19 No 4_Suppl_1

The most common subtype of aggressive non-Hodgkin’s lymphomais diffuse large B-cell lymphoma (DLBCL). Diffuse large B-cell lymphomarepresents a heterogeneous entity, with 5-year overall survivalrates ranging from 26% to 73%. Microarray gene expression studieshave confirmed that biologically distinct subgroups exist within DLBCL,and can be correlated with outcome. Initial management is usuallyguided by stage of disease at presentation. Approximately 25% of patientswith DLBCL present with limited-stage disease and are treatedwith combined-modality therapy (brief chemotherapy and involved-fieldradiation). Most patients present with advanced-stage disease and requiretreatment with an extended course of chemotherapy. The CHOP(cyclophosphamide, doxorubicin HCl, vincristine [Oncovin], prednisone)chemotherapy regimen has been the mainstay of therapy sinceits development in the 1970s, as more intensive chemotherapy regimensfailed to show additional benefit. The era of monoclonal antibodieshas transformed treatment practices for aggressive lymphoma andhas led to a significant improvement in outcome. A randomized trialcomparing the use of rituximab (Rituxan), a chimeric anti-CD20 IgG1monoclonal antibody, combined with CHOP chemotherapy vs CHOPchemotherapy alone for elderly patients with advanced-stage DLBCLdemonstrated a significant benefit for the combination approach. Thisfinding has now been confirmed in two additional randomized, controlledtrials and a population-based analysis, making CHOP andrituximab the standard of care for all newly diagnosed patients withDLBCL. Despite this advance, newer therapies are needed and manyare under active investigation. The insights gained from molecular techniquessuch as gene expression profiling should permit identificationof additional lymphoma-specific therapeutic targets and the developmentof novel agents that take into account underlying biology andallow for greater tailoring of therapy.

While some improvement was achieved by adding etoposide and shortening the treatment intervals from 3 to 2 weeks (CHOEP-14), best results in young good-prognosis patients (age-adjusted International Prognostic Index [IPI] = 0,1) have been achieved with six cycles of CHOP (cyclophosphamide, doxorubicin HCl, vincristine [Oncovin], prednisone)-like chemotherapy in combination with the anti-CD20 antibody rituximab (Rituxan). The role of additional radiotherapy in this setting remains to be determined. With this approach, 2-year eventfree survival rates of > 90% and overall survival of > 95% can be achieved in a very favorable subgroup (patients without IPI risk factor and no bulky disease), while further improvement is warranted for the less favorable subgroup (event-free survival only 77%). For young poorprognosis patients (age-adjusted IPI ≥ 2), the 5-year survival is around 50%, and progress has not been convincingly and specifically demonstrated in these patients. Ongoing studies will show whether dose-dense conventional or high-dose chemotherapy regimens requiring stem cell support in combination with rituximab will result in similar improvements of outcome as has been reported recently for young patients with good-prognosis aggressive lymphoma. In elderly patients, CHOP interval reduction from 3 to 2 weeks (CHOP-14) and the addition of rituximab to CHOP-21 achieved similar improvements in outcome. The ongoing RICOVER-60 (rituximab with CHOP over 60) trial of the German High-Grade Non-Hodgkin’s Lymphoma Study Group (DSHNHL) evaluates whether the combination of both approaches (R-CHOP-14) can further improve the prognosis of elderly patients.

The curability of the aggressive, large-cell lymphomas was first convincinglyreported by Levitt et al in 1972.[1] Patients with “reticulum cellsarcoma” were treated with a regimen that came to be known as COMLA(cyclophosphamide, vincristine [Oncovin], methotrexate, leucovorin, cytarabine[Ara-C]). A more commonly quoted paper was published in 1975 by DeVita et aldescribing the cure of advanced “diffuse histiocytic lymphoma” with COPP (cyclophosphamide,vincristine [Oncovin], procarbazine, prednisone).[2] During the 1970sthe CHOP regimen (cyclophosphamide, doxorubicin HCl, vincristine [Oncovin],prednisone) was described by McKelvey et al[3]; it quickly became the mostwidely used treatment for the aggressive large-cell lymphomas. Patients treatedwith two cycles of CHOP beyond documentation of a complete remission wereoften cured.[4]