A uniform activated B-cell–like immunophenotype might explain the poor prognosis of primary central nervous system lymphomas: analysis of 83 cases

Evaluation of BCL-6, CD10, CD138 and MUM-1 Expression in Diffuse Large B-Cell Lymphoma patients: CD138 is a Marker of Poor Prognosis

“…Previous studies that applied the same cutoff value of 10% reported a lower frequency of positive expression of CD10 [19% (Braaten et al, 2003), 34% (Fabiani et al, 2004), 43% (Xu et al, 2001), and 51% (Linderoth et al, 2003)] Other studies, using the 20%, 25%, 30% and 50% cutoff values reported a wide range of CD10 expression in DLBCL tumors (2 to 92%) (e.g. Harada et al, 1999;Ohshima et al, 2001;Pileri et al, 2003;Camilleri-Broet et al, 2006).…”

“…Some of the studies that did not find a statistically significant association between CD10 expression and DLBCL survival relied on a few individuals with positive CD10 expression to make the comparison (Braaten et al, 2003;Camilleri-Broet et al, 2006). However, other studies boasted respectable sample sizes of CD10 positive patients (ranging from 27 to 63) (Colomo et al, 2003;Linderoth et al, 2003;Fabiani et al, 2004;Liu et al, 2008) and still did not find a significant association between CD10 expression and DLBCL survival.…”

“…Berglund et al, 2005;Kojima et al, 2006;Oh and Park, 2006;Sjo et al, 2007). Three out of these ten studies (Braaten et al, 2003;Camilleri-Broet et al, 2006;Lin et al, 2006) scored seven or fewer negative samples for MUM-1 expression, severely reducing the statistical power of testing in these studies. Other studies, however, had considerable sample sizes of both MUM-1 positive and MUM-1 negative DLBCL patients and still failed to detect a significant difference in the survival of the two groups (Colomo et al, 2003;Saez et al, 2004;Berglund et al, 2005;Hoffmann et al, 2005;Sjo et al, 2007).…”

Gene expression profiling suggests primary central nervous system lymphomas to be derived from a late germinal center B cell

“…1,3 A major challenge of the present study was to distinguish between the gene expression profile of the tumor cells and the 'background' signature of the organ of manifestation, that is, brain versus secondary lymphatic organs, as this may lead to differences not attributable to characteristics of the tumor cells. In fact, the unsupervised analysis of gene expression profiles Figure 2 Expression analysis of genes previously reported to be differentially expressed between PCNSL and systemic DLBCL.…”

“…1,2 On the basis of their immunophenotype, PCNSLs were suggested to be more homogenous than systemic DLBCL. 3 However, also considering the limitations of semiquantitative immunohistochemistry with their varying rates of concordance for different markers, 4 it is still a matter of debate whether PCNSL corresponds to either the activated B-cell-like (ABC) or the germinal center B-cell-like (GCB) subtype as defined for systemic DLBCL or constitute a separate entity. This is mainly due to the fact that in most cases the tiny size of stereotactic biopsies precludes transcriptional profiling studies.…”