Cd10,Bcl-6 and Mum1 expression and the effect on prognosis in diffuse large b cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is one most seen subtype of lymphoma in the western world. This encompasses about 30-40% of non-Hodgkin lymphomas (NHL). Because DLBCL contains heterogenous clinic, morphologic, immunologic and cytogenetic properties it shows various clinical course and significant biologic heterogenity. In the studies which were used cDNA and oligonucleotid microarrays, DLBCL can be divided into significant biologic subgroups and prognostic groups. These are germinal center B cell (GCB), activated B cell (ABC) and type 3 gene expression profile types. Usually these kind of studies are long lasting and they reguires fresh frozen plasma samples, but these samples are present in a very limited group of cases. For this reason an algorithm has been established to differentiate GCB and ABC groups from each other by looking to expression of CD10, bcl-6, MUM1/IRF4 (MUM1) biomarkers in pathologic specimens. In present study we determined the GCB and ABC subgroup ratios by the algorithm of Hans et al and we examined the response ratios to rituximab containing chemotherapy in this patient subgroups.Totally 81 (39 male and 42 female) patients who were diagnosed as DLBCL between 1997 and 2009 were included in the study. The pathology specimens at the time of diagnoses were reached and retrospectively patients? records were examined. At pathologic specimens pf patients CD10, bcl-6, MUM1 and bcl-2 markers were examined by immunohistochemical method and specimens stained by 30% and higher were evaluated as positive. By using these markers patients were divided into groups 36 (44,4%) of patients were in GCB grup, 45 (55,6%) of patienst were in ABC grup. Bcl-2 was positive in 53 (65,4%) of patients. Thirty one (38,3%) of patients received CHOP (cyclophospamid, doxorubicine, vincristine, prednisone) like and 50 (61,7%) of patients received rituskimab-CHOP (R-CHOP) as chemotherapy protocol. In the survival analyzes overall survival (OS) for 5 years were significantly higher in international prognostic index (IPI) risk score low patients compared to high patients (p=0,006), in young patients compared to older ones (p=0,004) and in patients who responded to first treatment session well compared to patients not give good response (p<0,001). When the evaluated markers were compared for correlation, there was positive correlation between CD10 and MUM1, there was negative correlation between bcl-6 and MUM1. In the clinical properties the IPI risk score was positively and significantly correlated with the last situation of patiens (exitus or alive). Beside this, LDH levels were positively correlated with B symptoms. Between groups that formed according to markers, there was no significant difference by means of survival.In the era before rituximab, it was known that there was survival difference between subgroups established according to immunohistochemical markers. But in the rituximab era there are conflicting study results. For this reason survival difference caused by rituximab must be also taken into consideration and more reliable markers should be found.