OBJECTIVETo investigate the Bcl-2 protein and gene expression in diffuse large B-cell lymphoma (DLBCL), and analyze its correlation with immunosubtype and prognosis.

METHODSSeventy-three cases of DLBCL were performed immunohistochemistry analysis with a panel of antibodies CD3, CD10, CD20, Bcl-6, Bcl-2 and MUM-1, and classified into germinal center B-cell (GCB) type and non-GCB type. Fluorescence in situ hybridization (FISH) was employed to detect bcl-2 gene expression in 57 cases with chromosome translocation t (14;18).

RESULTSThe percentages of tumor cells expressed CD10, Bcl-6, MUM-1 and Bcl-2 were 15.1%, 38.4%, 71.2% and 79.2%, respectively. 16 cases (21.9%) were GCB type and the rest (78.1%) were non-GCB type. 16 of 57 cases (28.1%) were t (14; 18), including 5 of GCB type (31.2%) and 11 of non-GCB type (68.2%). The expression of Bcl-2 protein was correlated with immunological subtype (P = 0.035), but not with survival time (P = 0.253). Between the t(14;18) positive and negtive groupes, there was significant difference for survival time (P = 0.022), but no difference for immunological subtype (P = 0.340). There was no correlation between Bcl-2 protein and t(14;18).

CONCLUSIONSGCB type DBLBCL with expression of Bcl-2 protein had a poor prognosis. t(14; 18) positive BLBCL had poor prognosis. The expression of Bcl-2 protein and t(14; 18) are usually discordant.