[Prevalence of germinal center B-cell-like and non-germinal center B-cell-like types of diffuse large B-cell lymphoma in Shanghai, China].

Objective: To study the prevalence of germinal center B-cell-like (GCB) and non-GCB-like types of diffuse large B-cell lymphoma (DLBCL) in Chinese patients.

Methods: Immunohistochemical study for CD10, bcl-6, MUM1, GCET1 and FOXP1 was performed on 124 cases of DLBCL from Shanghai, China. The Hans algorithm and Choi algorithm were applied to classify DLBCL into GCB and non-GCB-like types. Fluorescence in-situ hybridization (FISH) for t (14;18) and bcl-6 gene rearrangement was also carried out on 118 cases.

Results: Of the 124 DLBCL cases studied, 27 cases (22%) showed a GCB-like type and 97 cases (78%) showed a non-GCB-like type, when using Hans algorithm. On the other hand, 34 cases (27%) belonged to GCB-like type and 90 cases (73%) belonged to non-GCB-like type when applying Choi algorithm. The prevalence of GCB-like type was significantly lower than that of non-GCB-like type (P=0.0001). Only four cases (3%) were positive for t (14;18), and three of them were classified as GCB-like type. bcl-6 rearrangement was found in 46 cases (39%) and more frequently encountered in the GCB-like type. There is no relationship between bcl-6 gene rearrangement and bcl-6 protein expression.

Conclusions: The GCB-like type of DLBCL is significantly less common than non-GCB-like type in Chinese population. This phenomenon is possibly related to the low frequency of t (14;18).