Immunophenotypic and genetic characteristics of diffuse large B-cell lymphoma in Taiwan

Abstract

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma type. The immunophenotypic and genetic features of DLBCL in Taiwan have not been characterized. Methods: In this study, we performed immunohistochemical analysis and interphase fluorescence in situ hybridization (FISH) using tissue microarray sections to investigate a cohort of unselected DLBCL cases in a single institution in Taiwan from 1990 to 2010. Results: Of the 153 cases investigated, CD10, bcl-6, and MUM1 were expressed in 16.3%, 71.2%, and 71.9% cases, respectively, with 27.5% (n = 42) of cases being classified as having a germinal center B-cell (GCB) origin by the Hans algorithm. By FISH analysis, 19.6%, 4.6%, 26.1%, and 3.9% cases showed rearrangement at IGH, BCL2, BCL6, and MYC loci, respectively, including three (2.0%) cases of double-hit lymphoma. As compared with the non-GCB tumors, GCB tumors more frequently expressed CD10 (p < 0.001) and bcl-6 (p = 0.001) with less frequent expression of MUM1 (p = 0.007). Moreover, GCB tumors more frequently exhibited rearrangement at the BCL2 (p = 0.024) and MYC (p = 0.038) loci than non-GCB tumors. However, there was no survival difference between these two groups. Conclusion: In this first series of DLBCL evaluation from Taiwan, we found that the relative frequency of GCB tumors among DLBCL was low in most East Asian countries. There is a wide range of BCL2 rearrangement rates, higher in the West and lower in East Asia. A larger and/or national study is warranted to better understand the immunophenotypic and molecular features of DLBCL in Taiwan and their respective impact on patient survival.

Keywords

• diffuse large B-cell lymphoma
• fluorescence in situ hybridization
• germinal center B cell
• immunohistochemistry
• Taiwan