OBJECTIVETo study the immunohistochemical classification and prognosis of diffuse large B-cell lymphoma (DLBCL).

METHODSA total of 148 cases of DLBCL were classified into germinal center B-cell-like (GCB) and non-GCB/activated B-cell-like (ABC) subtypes by Hans, Choi and Tally immunohistochemical stain algorithms. The clinical features and survival data of GCB and non-GCB/ABC subtypes were compared. Multivariate analysis about clinical features and results of immunohistochemical stain algorithms was carried out by using Cox regression, with overall survival as the outcome.

RESULTSThe prevalence of GCB subtype was significantly lower than that of non-GCB/ABC subtype, as classified by whichever algorithms in the 148 DLBCL cases studied. The prevalence of GCB subtype by Tally algorithm was lowest. The prevalence of GCB subtype (19 cases, 16.7%) was also significantly lower than non-GCB/ABC subtype (95 cases, 83.3%; P = 0.000 1) in the 114 (77.0%) concordant cases by the three algorithms. There was no difference between GCB and non-GCB/ABC subtypes by the three algorithms in five-year overall survival rate and survival curve of the 80 DLBCL patients with follow-up data available (P > 0.05). Primary gastric DLBCL tended to show a higher prevalence of GCB subtype, a better five-year overall survival rate and survival curve than the other groups. Multivariate analysis showed that patient age (HR = 1.036, P = 0.001) and tumor stage (HR = 1.997, P = 0) were also significantly adverse predictors of overall survival.

CONCLUSIONThe Hans, Choi and Tally immunohistochemical stain algorithms cannot effectively classify Chinese DLBCL into different prognostic subtypes. Primary gastric DLBCL has different immunophenotype and outcome, as compared with DLCBL in other sites.