JC EH lin xp ematopathol
Original Article
INTRODUCTIONDiffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), and accounts for 30%-40% of all adult NHL.1,2 The diagnostic category of DLBCL is heterogeneous, and the clinicopathological and molecular genetic diversity of DLBCL was reflected in the 2008 WHO classification of lymphomas. Furthermore, the updated revision in 2016 3 described many subgroups and entities based on distinct morphological, immunophenotypical, molecular and clinical parameters. Although DLBCL is a potentially curable disease with current therapy, particularly for those who achieve complete remission with first-line treatment, approximately 40% of patients will die of relapsed or refractory disease. 2,4 Factors that contribute to the outcome include age, socioeconomic conditions, comorbid conditions, performance status and several clinical features. 5,6 Therefore, it is necessary to stratify patients according to their prognostic risk in a suitable and cost-effective manner.Prognostic factors in DLBCL include standard and wellestablished factors such as the International Prognostic Index (IPI; with its variants as the original, R-IPI, age-adjusted IPI and NCCN-IPI), immunohistochemistry for cell-of-origin (e.g. Hans, Choi and Tally algorithms), imaging by positron emission tomography (PET)/CT scans, fluorescence in situ The estimation of clinical prognosis for diffuse large B-cell lymphoma (DLBCL) with a quick, cost-efficient method is necessary because of the clinical heterogeneity of this disease, which leads to death, relapsed or refractory disease in approximately 40% of patients. We analyzed 320 cases diagnosed from 2007 to 2013 treated with R-CHOP therapy at Tokai University Hospital and associated institutions. DLBCL was classified according to the cell-of-origin using the Hans algorithm [germinal center B-cell-like (GCB) vs non-GCB subtypes], and into 6 subgroups derived from combinations of CD10, BCL6 and MUM1 markers. The percentage of GCB and non-GCB (NGCB) subtypes was 35% and 65%, respectively. GCB-DLBCL was characterized by lower BCL2 immunohistochemical expression, extranodal sites <1, better therapeutic response, and favorable overall survival (OS) and progression free survival (PFS) (P<0.01). The most frequent subgroup was NGCB-1 (CD10 -, 2%). In comparison with GCB-2 and GCB-3 (both MUM1 -), the GCB-1 (MUM1 + ) was characterized by favorable PFS (5-year PFS 84% vs 65%, OR 0.368, P<0.05), independent of high LDH (associated with unfavorable PFS, OR 7.04, P<0.01) in the multivariate analysis. This predictive value of MUM1 was independent of CD10. Interestingly, triple-negative NGCB-3 tended to have a more favorable prognosis than the other NGCB subgroups. In conclusion, the Hans classifier is a valid method to evaluate the prognosis of DLBCL NOS. In the GCB subtypes, GCB subtypes, MUM1-positivity is associated with a more favorable outcome (PFS).