Marie Parrens

Abstract We herein present an overview of the upcoming 5 th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4 th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5 th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

BACKGROUND: In angioimmunoblastic T-cell lymphoma, symptoms linked to B-lymphocyte activation are common, and variable numbers of CD20(+) large B-blasts, often infected by Epstein-Barr virus, are found in tumor tissues. We postulated that the disruption of putative B-T interactions and/or depletion of the Epstein-Barr virus reservoir by an anti-CD20 monoclonal antibody (rituximab) could improve the clinical outcome produced by conventional chemotherapy. DESIGN AND METHODS: Twenty-five newly diagnosed patients were treated, in a phase II study, with eight cycles of rituximab + chemotherapy (R-CHOP21). Tumor infiltration, B-blasts and Epstein-Barr virus status in tumor tissue and peripheral blood were fully characterized at diagnosis and were correlated with clinical outcome. RESULTS: A complete response rate of 44% (95% CI, 24% to 65%) was observed. With a median follow-up of 24 months, the 2-year progression-free survival rate was 42% (95% CI, 22% to 61%) and overall survival rate was 62% (95% CI, 40% to 78%). The presence of Epstein-Barr virus DNA in peripheral blood mononuclear cells (14/21 patients) correlated with Epstein-Barr virus score in lymph nodes (P<0.004) and the detection of circulating tumor cells (P=0.0019). Despite peripheral Epstein-Barr virus clearance after treatment, the viral load at diagnosis (>100 copy/μg DNA) was associated with shorter progression-free survival (P=0.06). CONCLUSIONS: We report here the results of the first clinical trial targeting both the neoplastic T cells and the microenvironment-associated CD20(+) B lymphocytes in angioimmunoblastic T-cell lymphoma, showing no clear benefit of adding rituximab to conventional chemotherapy. A strong relationship, not previously described, between circulating Epstein-Barr virus and circulating tumor cells is highlighted.

BACKGROUND: As rituximab combined with CHOP improves complete remission and overall survival in diffuse large B-cell lymphoma, intensified chemotherapy followed by autologous stem-cell transplantation has also been advocated for high-risk patients. The aim of this study was to establish whether or not combining rituximab with high-dose chemotherapy and auto-transplantation also benefits patient survival. DESIGN AND METHODS: The LNH2003-3 study was a phase II trial including diffuse large B-cell lymphoma patients with 2 or 3 International Prognostic Index factors. They received four cycles of intensive biweekly chemotherapy with rituximab, doxorubicine, cyclophosphamide, vindesine, bleomycine, prednisolone (R-ACVBP) followed by auto-transplantation in responding patients. Two hundred and nine patients under 60 years of age were included in the study and 155 responding patients underwent auto-transplantation. In addition, a case-control study was performed by matching (1:1) 181 patients treated with R-ACVBP with ACVBP patients not given rituximab but submitted to auto-transplantation from the previous LNH1998-3 trial. RESULTS: With a median follow up of 45 months, 4-year progression-free survival and overall survival were estimated at 76% (CI: 69-81) and 78% (CI: 72-83), respectively. There was no difference between patients with 2 or 3 International Prognostic Index factors. Four year progression-free survival was significantly higher in R-ACVBP than ACVBP patients (74% vs. 58%; P=0.0005). There was also a significant increase in 4-year overall survival (76% vs. 68%; P=0.0494). CONCLUSIONS: In high-risk diffuse large B-cell lymphoma patients, treatment with R-ACVBP followed by auto-transplantation results in a 78% 4-year overall survival which should be compared to other approaches.

We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.