The GCB subtype of diffuse large B-cell lymphoma is less frequent in Asian countries.

Patients with the germinal center B-cell-like (GCB) subtype of diffuse large B-cell lymphoma (DLBCL) have a significantly better survival rate than those with non-GCB DLBCL. Several studies have examined the proportions of GCB and non-GCB subtypes in large series of DLBCL patients, but it remains unclear if these proportions are the same in different countries. We performed an immunohistochemical analysis of the numbers of GCB and non-GCB subtypes in a large number of patients with DLBCL in Japan and compared the results with literature data for other countries. We found that 71 of 248 patients (29%) had the GCB phenotype and 177 patients (71%) had the non-GCB subtype of DLBCL among our patient population. Assessment of data collected from other studies showed that 31% of DLBCL patients (102/330) have the GCB subtype in Asian countries, but 50% (206/416) express GCB phenotypes in Western countries; based on these data, the occurrence of the GCB subtype of DLBCL was significantly less in Asian countries (p<0.001). Since patients with the GCB phenotype of DLBCL have better survival, future studies of DLBCL should recognize the difference in the proportions of GCB and non-GCB subtypes of DLBCL between Asian and Western populations.