[Subgrouping and outcome prediction of diffuse large B-cell lymphoma by immunohistochemistry].

Objective To categorize diffuse large B-cell lymphoma(DLBCL)into germinal center B cell-like(GCB)and non-germinal center B cell-like(non-GCB)subgroups by immunohistochemistry; and to investigate the underlying prognostic significance.Methods Immunohistochemical study for CD10, bcl-6 and MUM1 was performed on 133 cases of DLBCL.The cases were then categorized into GCB and non- GCB subgroups.The 5-year overall survival and 5-year progression-free survival rates were compared between the GCB and non-GCB groups,and among the cases with different immunohistochemical expression or with different IPI.Results Amongst the 133 case studied,CD10 was expressed in 33.1%,while bcl-6 was positive in 34.6% and MUM1 in 45.1%.CD10 expression had a favorable impact on 5-year overall survival(P=0.041)and 5-year progression-free survival(P=0.031).On the other hand,bcl-6 expression had a favor able impact on 5-year progression-free survival(P=0.044).Expression of MUM1 carried an adverse effect on 5-year overall survival(P=0.031)and 5-year progression-free survival(P= 0.028).GCB immunophenotype was demonstrated in 40.6% of the cases,while 59.4% showed a non-GCB profile.GCB DLBCL had a significantly longer 5-year overall survival(P=0.004)and 5-year progression- free survival(P=0.003),as compared with the non-GCB group.When dividing the cases into two groups according to their IPI score(IPI=0 to 1 and IPI=2 to 5),it turned out that the 5-year overall and progression-free survival rates of the GCB group were significantly higher than those of the non-GCB group (P=0.019 and 0.014 respectively in cases with IPI of 0 to 1 and P=0.006 and 0.009 respectively in cases with IPI of 2 to 5).The non-GCB cases with a IPI of 2 to 5 had the poorest prognosis.Conclusion DLBCL subgrouping by immunohistochemistry and analysis of the subgrouping with IPI is feasible and useful in predicting clinical outcome.